Download Section (c) – The Structure of atoms

Unit 1
Section (a) – Particles.
1. Everything in the world is made from about ................. elements.
2. All of the elements are listed in the ............................................ ............................................ .
Each element has its own symbol.
Symbol
Element
Ag
Cu
sodium
oxygen
3. A column of elements is called a ................................... A row of elements is called a ......................................
4. Information on elements can be found in the Periodic Table. There are eight groups of elements and
some are given special names.
Group number
Name of group
Description of elements in this group
alkali metals
7
very reactive non-metals
8
The metals in the centre of the Periodic Table between groups 2 and 3 are called the ...........................................
Metals. Elements in the same group have ....................................... chemical properties.
5. Elements can be classified as metal or .......................................... Examples of metallic elements include
copper, .................................. and ........................................................ . Examples of non-metal elements include
sulphur ................................... and ...................................................... .
6. Elements can be classified as naturally occurring or as ................................................
Two examples of
naturally occurring elements include ...................................... and ................................................... .
Plutonium and Americium are examples of .......................................................... elements.
7. Elements can be classified as solid, ..................................... or ......................... at room temperature.
Only two elements are liquid at room temperature - .................................... and ....................................... .
The elements which are gases at room temperature are hydrogen, helium, nitrogen, oxygen,
and all the ................................. gases in group 8.
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8. Compounds are made when .......................... or more elements join together. Compounds with names ending
in –ide usually only contain only .......................... elements. Compounds with names ending in –ite or –ate
also contain the element ...................................... .
9. In a chemical reaction a ....................... substance is formed. A chemical reaction can be identified by

a ............................................
change

a ............................................ being formed (effervescence)

a ............................................ being formed (precipitate)

an ............................................ change (e.g. heat and .............................)
10. A reaction in which energy is ........................ ..................... to the surroundings is said to be an exothermic
reaction. In an exothermic reaction the products have ......................... energy than the reactants.
11. A reaction in which energy is ........................ ..................... from the surroundings is said to be an endothermic
reaction. In an endothermic reaction the products have ......................... energy than the reactants.
12. When two, or more substances come together without reacting a .................................... is formed.
13. Air is a mixture of the gases ......................................... and .....................................................
14. The test for oxygen is that it ..............................................................................................................
This test does not work in air as there is not enough ........................................ in air for a positive result.
15. When a solid (e.g. salt) is dissolved in a liquid (e.g water) a ................................. of salt and water
is formed. The liquid (water) is called the .................................. and the solid (salt) is celled the
..................................... . A solid that dissolves in water is said to be .......................... A solid that does not
dissolve in water is said to be .......................................
A solution becomes ....................................... when no more solid can be dissolved.
The concentration of a solution is a measure of how much solute is dissolved in the solvent. If the
amount of solute dissolved is large it is a ....................................... solution. Small amounts of solute
dissolved form . ...................................... solutions.
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Section (b) - Reaction Rates
1. Reaction ...................... can be determined by measuring changes in concentration, mass or volume.
2. The rate of a reaction can be calculated using the relationship
change in ............................................
rate =
the units are mol l-1 s-1
time taken for change
3. The rate of a reaction is proportional to 1/...............................
(units s-1). If the rate of the reaction is
high the time taken will be ......................... . If the rate of the reaction is low the time taken for the
reaction will be ............................... .
4. The speed of a reaction can be speeded up using four methods

using a
..............................................

increasing the ......................................... at which the reaction is carried out.

increasing the .......................................... of a solution

increasing the ........................................ area of a solid by using .................................. particles.
5. By increasing the concentration of one of the reactants the number of collisions between reactant particles
will be ............................................. .
By increasing the surface area of a solid by using ............................ particles the number of collisions with
the surface of the solid will ................................
The greater the number of collisions between reactant particles the ............................ the reaction.
6. A ................................... speeds up a reaction but is not used up in the reaction.
Catalyst
Used in making
Ammonia
Platinum
Most cars now have catalytic ...................................... to turn ...................................... exhaust
gases into less harmful gases. The metals ................................................, rhodium and palladium are
used in catalytic converters. In the catalytic converter harmful carbon monoxide and oxides of nitrogen
are converted into less harmful .................................... ......................................... and nitrogen.
7. A homogeneous catalyst is in the ............................ physical state as the reactants. A ..........................................
catalyst is in a different physical state to the reactants. In a heterogeneous catalyst one of the reactants
is adsorbed onto the surface of the solid catalyst. One of the reactants matches the shape and size of
part of the catalysts surface called the ............................. site. The effectiveness of a catalyst can be reduced
by a catalyst .................................... This is a chemical which blocks the .......................... sites.
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8. Catalytic converters in cars have to use ...................................... petrol as lead would poison the
platinum catalyst. If this happened the catalyst would have to be ..............................................
9. Enzymes are catalysts which work in ............................. ................................. . The enzyme, .................................
found in yeast is used to convert sugar into ............................. in a process called fermentation. The
enzyme, ............................... is used in biological washing powders.
Section (c) – The Structure of atoms
1. Every element is made up of very small particles called ...................................
2. Information about the different particles found in an atom of an element is summarised in this table.
Particle
Mass (amu)
Proton
Charge
Position in atom
1
Neutron
Electron
3. For an atom to be neutral the number of protons and electrons are ................................. .
The atomic number of an element is the number of ................................ in an atom of the element.
The .......................... number of an element is the number of protons + the number of ....................................
in an atom of the element.
The relative atomic mass of an element is the ...................................... mass of all its atoms.
4. . Information on atoms of different elements can be show in a table.
Element Symbol
Ca
F
40
20
Atomic No.
Mass No.
Protons
Neutrons
Electrons
Electron Arrangement
Group No
Ca
19
9
F
5. Elements in the same group in the Periodic Table have the same number of ................................. in their outer
energy level. Elements with the same number of ....................................... in their outer energy level have
......................................... chemical properties.
6. Isotopes are atoms having the same ............................. number but different ......................... numbers.
Most elements consist of a number of different .......................................................
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7. Most elements consists of a number of ........................................ isotopes.
The relative atomic mass of an element is the ...................................... mass of all its atoms.
Because it is an average the relative atomic mass of an atom is rarely a ........................... number.
Section (d) Bonding, structure and properties
1. Electrons are arranged in ........................................... levels. The first electron .................................. level can hold
up to .................. electrons. The second and third electron energy levels can hold ................................. electrons.
2. Atoms can be held together by ............................ In forming bonds atoms can achieve a .............................
electron arrangement.
3. Metallic bonding is an electrostatic attraction between the ................................charged nucleus and
the delocalised outer ..................................................
4. Atoms of non-metal elements bond together by sharing electrons – this type of bond is known as
a ......................................... bond. In a ..................................... bond the atoms are held together by an
electrostatic attraction between the ........................................ charged shared electrons and the
............................................ charged nuclei.
5. Polar-covalent bonds are formed when the attraction of the atoms for the bonded electrons is
..................................................... The covalent bonds in water are highly .........................................
6. Ionic bonding usually occurs between metal atoms and ........................................ atoms.
Positive ions are formed when metal atoms .............................. electrons. Negative ions are formed
when non-metal ions .......................... electrons.
Ionic bonding is an electrostatic attraction between the .......................................... charged metal ions
and the ........................................... charged non-metal ions.
7. A group of atoms held together by covalent bonds is called a ...............................................
Some molecules contain two joined by a covalent bond. These molecules are called .......................................
molecules.
Examples of diatomic molecules are iodine (I2), bromine(............),.................................. (Cl 2),
........................................ ( ............), ........................................ ( ............), ........................................ ( ............),
and hydrogen (H2) among the elements and carbon monoxide (........) among the compounds.
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8.
............... der ........................ forces are weak forces of attraction that exists between covalent
molecules.
.................... der ................... forces are much .................................. than all other types of bonding.
9. A metallic structure consists of a giant .................................... of positive ions surrounded by
...................................................... outer electrons.
-
+
delocalised outer
...............................
-
-
+
+
+
-
-
+
+
+
-
+
+
+
-
-
-
+
+
+
+
+
-
-
-
+
-
+
lattice of .........................
charged nuclei
+
-
-
10. A covalent molecular structure consists of discrete molecules with ............................... bonds
between the atoms inside the molecule and weak ...................... ..................... ............................. for ces
between the molecules.
eg
H
H
covalent bond
H
H
van der Waals force
11. A covalent network structure consists of a giant ........................................ of covalently bonded atoms.
covalent bond
eg diamond
12. An ionic structure consists of a giant .................................... of oppositely ...................................... ions.
eg sodium chloride
13. An electric current in a ……………….…… is a flow of electrons. All metals and the non-metal element
…………………………………………………. conduct electricity. In a d.c. supply the electrons flow from the
…………………………………………………. electrode to the …………………………………………………. electrode.
Metal compounds do not conduct in the …………………………………………………. state but they will conduct when
……………………………………………… or when they are ……………………………………………… in water.
Passage of electricity through an ionic solution causes the ionic compound to break down – this is called
……………………………………………… .
Compounds formed between a metal and a non-metal have …………………………………………… bonding.
Solid ionic compounds do not conduct as the …………… are not free to …………………… .
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14. Metal atoms can form ………………………………………… charged ions by the metal atom ……………………………… electrons.
Non-metal atoms can form ……………………………………… charged ions by the non-metal atom ……………………………………
electrons.
Compounds which contain only non-metal atoms are usually made up of covalent ……………………………………………….
Compounds which are made up of a metal bonded to non-metal(s) are usually ionic. Ionic solids exist
as large ……………………………………………… containing millions of charged ions. As the ionic network contains
many millions of strong ionic bonds the melting point of these compounds is …………………………
Most covalent compounds exist as ………………………………………………. Inside the molecule the atoms are
bonded by a strong ……………………………………………… bond. Between the molecules there are only weak
…………………… ……………….. ……………………………. forces. This means that these compounds have ………………..
melting and boiling points.
A few covalent substances like diamond (a form of the element ……………………………………) and silicon dioxide
(sand) are made up of a covalent ……………………………………………… These substances have only strong
……………………………………………… bonds and so have very ……………………………… melting points.
15. Most ionic compounds ………………………………. in water. Most covalent compounds are ………………………………………………
in water.
16. During electrolysis, electricity is used to break apart an …………………………………………… compound which is molten
or in solution. The positively charged ions are attracted to the ……………………………………………… charged
electrode where they gain …………………………………….. . The negatively charged ions are attracted to the
……………………………………………… charged electrode where they ………………………… electrons.
Section (e) – Chemical Formulae
1. We can use valencies to work out the chemical formula of a compound.
e.g. sodium chloride
NaCl
iron(II) sulphate
..........................
calcium bromide
......................
iron(III) sulphate
...........................
lead(IV) oxide
......................
ammonium nitrate
...........................
magnesium hydroxide ......................
calcium oxide
..........................
sodium sulphate
aluminium oxide
...........................
......................
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2. Sometimes we can work out the formula of a compound from its name. When this is the case
we do not use valency. The name of the compound contains a prefix which tells us how many atoms
of each element are present.
e.g.
carbon monoxide
CO
phosphorus trichloride
..........................
carbon dioxide
......................
phosphorus pentachloride
..........................
sulphur trioxide
......................
dinitrogen monoxide
..........................
dinitrogen monoxide
......................
carbon tetrachloride
.........................
3. You must be able to balance an equation
e.g. Balance the equations below:(a)
Na
(b)
CH4
+
+
S
Na2S
O2
CO2
+
H 2O
Section (f) – The Mole
1. You must be able to use the relationship shown below
mass
n
gfm
to calculate
(a) the number of moles of sodium hydroxide (NaOH) in 200g of sodium hydroxide.
(b) the mass of sodium carbonate (Na2CO3) present in 0.05 moles of sodium carbonate.
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2. You must be able to carry out calculations using a balanced equation.
e.g. What mass of carbon dioxide is formed when 4kg of methane is burned?
CH4 + 2O2
CO2
1 mole
1 mole
(1 x 12) + (4 x1)
So
So
+ 2H2O
(1 x 12) + (2 x 16)
16 g
44 g
16 kg
44 kg
4
44 x
16
4 kg
= 11 kg
Examples for practice.
(a) Calculate the mass of oxygen that can be formed when 68g of hydrogen peroxide (H2O2) decomposes.
2H2O2
2H2O
+
O2
(b) Calculate the mass of iron that can be formed from 480 kg of iron(III) oxide.
Fe2O3(s) + 3CO(g)
2Fe(s) + 3CO2(g)
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Unit 2
Section (a) – Fuels
1. A ............................... is a substance which gives out energy when it burns. Burning is also called
............................................ . when a fuel burns it combines with ........................................ from the air to
form an oxide. Burning is an ........................................ reaction as it gives out energy.
2. The fossil fuels are ........................................, ........................................ and natural gas. Crude oil and
natural gas are mixtures of compounds called .............................................. . Hydrocarbons contain
only the elements ........................................ and ........................................ .
3. Hydrocarbons burn in a plentiful supply of air to produce ................................................ ...................................
and .......................................... .
The test for carbon dioxide is that it turns ......................... ....................................... milky (or chalky).
4. Carbon (soot) and the very poisonous gas, ................................... ........................................... (CO) are produced
when hydrocarbons burn in a limited .................... supply.
5. ........................................ and ...................................... from the air react inside a car engine to form oxides of
nitrogen which are poisonous gases.
6. The burning of some fuels containing sulphur releases .................................. ................................... (SO 2),
a poisonous gas, into the atmosphere.
7. Air pollution from the combustion of hydrocarbon fuels can be reduced by the use a ........................................
converter which speeds up the conversion of harmful gases into ......................................... gases.
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8. Crude oil is separated by a process called .................................. distillation into fractions in an oil refinery.
A fraction is a group of hydrocarbons with .................................. points within a given range.
Fraction
name
Number of carbon
atoms per molecule
Use of
fraction
refinery gas
1-4
bottled gas
gasoline
5-12
...............................
kerosene
9-16
..............................
diesel
13-25
..............................
fuel oil
25-70
...............................
residue
more than 70
..............................
Of these fractions the ....................................... fraction is the most flammable.
The ........................................ fraction is the most viscous (thick and sticky).
The greater the number of carbon atoms in the molecule the ................................. the boiling point of the fraction.
Section (b) – Nomenclature (naming) and formulae.
1. Alkanes are saturated hydrocarbons having the general formula ...................................
Saturated hydrocarbons contain only .................................... covalent bonds.
2. Cycloalkanes are saturated hydrocarbons having the general formula ...................................
Cycloalkanes have a ........................... ring of carbon atoms
3. Alkenes are unsaturated hydrocarbons having the general formula ...................................
Unsaturated hydrocarbons contain a carbon to carbon .......................... covalent bond.
4. You must be able to give the systematic names, molecular formulae, condensed and structural
formula of the alkanes, cycloalkanes, alkenes with up to 8 carbon atoms per molecule.
H
.
e.g
H
H
H
H
H
C
C
C
C
H
H
H
H
H
H
H
is called ........................................................
H
C
H
H
C
C
C
H
H
H
H
................................ ..............
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H
C
H
C
H
C
H
H
C
C
H
H
H
H
is called ........................................................
..............................................
Further examples for practice:-
Give the letters for the correct answers. In some questions there is more than one correct answer.
Identify:
(a) an alkane.
……………………
(b) an alkene
……………………
(c) a cycloalkane
……………………
(d) an unsaturated hydrocarbon
……………………
(e) a hydrocarbon with the formula C3H6.
……………………
(f) two hydrocarbons with the same molecular formula
……………………
(g) the hydrocarbon which is an isomer of E
……………………
(h) a hydrocarbon which quickly decolourises bromine solution
……………………
(i) two hydrocarbons which are isomers
……………………
(j) methane
……………………
(k) ethane
……………………
5. A homologous series is a set of compounds with the same .................................. formula and
similar .................................................. reactions.
6. Isomers are compounds with the same ................................... formula but different ......................................
formulae.
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7. Alkanols contain the ......................................... (-OH) functional group and have names that end in –ol.
The general formula for straight chain alkanols (alcohols) is ...........................................
In the space below draw extended structural formulae for the isomers propan-1-ol and propan-2-ol.
8. Alkanoic (carboxylic) acids contain the ......................................... ( -COOH) functional group. Alkanoic acids have
a name ending of -......................... acid.
O
H
H
H
eg
H
C
C
C
H
H
H
C
O
H
is called ..................................................... acid.
9. Esters contain the ester functional group ( .....................) and have a name ending of –oate.
The first part of an esters name comes from the parent alchol eg ethanol gives an .......................
ester.
The second part of the ester name comes from the parent carboxylic acid eg propanoic acid gives
a ......................................... ester.
eg
H
H
H
C
C
H
H
O
O
+
H
H
O
H
C
H
.......................................
+ ............................... acid -->
H
H
C
C
H
H
O
O
+
C
H
O
H
.............................................
+
water
Section (c) – Reactions of carbon compounds
(i) Hydrocarbons
1. It is possible to tell an unsaturated alkene from a saturated alkane, or cycloalkane by the fact that
the alkene quickly ......................................... bromine solution while the others do not.
2. Alkenes react quickly by addition across the carbon to carbon ................................. bond.
3. Alkenes can undergo addition of ................................................. (hydrogenation) to form alkanes.
4. Alkenes can undergo addition of .............................................. (halogenation) to form dihalogenalkanes.
eg
H
H
C
H
H
C
H
Br
H
Br
H
H
H
C
C
C
C
Br
Br
H
H
C
H
+
C
H
H
H
H
.................................................. +
bromine
-->
13
...............................................................
H
5. Alkenes undergo addition of steam (hydration) to form alcohols.
H
H
C
C
H
H
C
H
+
H
O
H
.....................................
H
.....................................
+
water
H
H
H
H
C
C
C
H
H
H
O
H
.....................................
6. Fractional distillation of crude oil produces more ...........................-chain hydrocarbons than there is a
demand for.
Cracking is an industrial process for producing a mixture of ......................................., more useful molecules
some of which are unsaturated. In catalytic cracking the catalyst allows the process to occur at a
................................................ temperature.
7. The diagram shows how cracking can be carried out in the laboratory.
Label the diagram using the words below
heat
aluminium oxide catalyst
liquid paraffin
bromine solution
(ii) Alcohols
1. Carbohydrates in fruits and vegetables can be turned into alcohol by a process called .....................................
The breakdown of glucose to alcohol (ethanol) by fermentation is catalysed by the enzyme, ..............................,
present in yeast.
2. High concentrations of alcohol stop the enzyme working and so fermentation can only produce
alcoholic drinks with about 12% alcohol. To obtain alcoholic drinks (spirits) with an higher alcohol
concentration (40%) the alcohol and water are separated by ............................................. .......................................
The alcohol and water are able to be separated in this way as they have different .......................................
points.
3. Alcoholic drinks, if taken in excess, have damaging effects on the ...................... and ........................
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4. To meet market demand ethanol is also made by the catalytic hydration (addition of ..........................)
of ethene.
C2H4(g) + H2O(g)
.............................
5. Ethanol can be dehydrated (removal of .............................) to ethene. In the reaction the ethanol vapour
is passed over a heated ........................................ .......................................... catalyst.
6. Ethanol obtained from sugar cane is a ............................................. source of energy.
(iii) Esters.
1. Esters are made in a ................................................... reaction between and alcohol and a
...................................................... acid.
eg
O
H
H
H
C
C
+
H
H
O
O
C
+
H
H 2O
....................................
H
H
.................................... acid
The
...........................
methylethanoate + water
shows that the reaction is ....................................................
2. The breaking of an ester into an alcohol and a carboxylic acid is an example of a .................................
O
reaction.
H
C
eg
H
H
C
C
H
O
H
C
H
+ H2O
C
H
H
H
..............................
H
.............................
In the diagram above circle the ester group in the ester molecule shown.
Section (d) Plastics and synthetic fibres.
1. Most plastics and synthetic fibres are made from chemicals obtained from ................ ........................
2. Examples of plastics include polythene, poly.........................., perspex, P..V.C., ..........................
Bakelite, formica and silicones.
3. Kevlar is very light and ....................................... Kevlar is used to make ...................................................... vests.
4. Poly(ethenol) is a ............................. soluble polymer. It is used to make dissolving hospital laundry
bags.
5. Examples of synthetic fibres include nylon and .................................................
6. Biopol is a ........................................................ polymers. However, most plastics are non-........................................
and cause a ................................ problem when thrown away .
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7. When they burn plastics produce ...................................... gases. e.g polyurethane forms ............................................
............................................., PVC produces carbon monoxide and ................................
........................................
8. Some plastics soften on heating and can be reshaped. These plastics are said to be ..........................................
Some plastics do not soften on heating – they are called ............................................. polymers.
9. Addition polymers are made from small .................................................. monomer molecules. The unsaturated
monomer molecules are produced by ............................................... long chain hydrocarbon molecules.
When many small monomer molecules join together they form a long chain molecule called a .................................
Addition polymerisation occurs when many unsaturated monomers join to form a ...........................................
Monomer
Polymer
Ethene
Poly(ethene)
Propene
Poly(vinylchloride)
10. In the formation of an addition polymer, the carbon to carbon ................................. bond in the monomer
molecule breaks and becomes a ................................... bond in the polymer.
This is propene
CH3
H
C =
C
H
H
Show how three propene monomer molecules link together to make poly(propene).
11. Condensation polymers are made from monomers with ...................... functional groups per molecule.
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12. Polyesters are condensation polymers made by a reacting a ................................... (two –OH groups)
with a ........................................... ( two –COOH) groups
eg Shown below a two molecules of ethane-1,2-diol and benzene-1,4-dicarboxlic acid
Complete the diagram to show part of the polyester formed when these 4 molecules react.
Once drawn, circle the ester links in the polymer.
O
H
O
H
H
C
C
H
H
O
C
O
H
O
C
O
O
H
H
O
H
H
C
C
C
O
H
C
O
H
H
O
O
H
H
H
13. Polyesters are manufactured for use as textile fibres and as resins.
Polyesters used as textile fibres have a ....................................... structure. Polyesters used as resins
have a ........................................ - ............................................. 3 dimensional structure.
14. An amine is a molecule which contains the ............................... (-NH2) functional group.
15. Polyamides are condensation polymers made by reacting a diamine (a molecule with two ...............
groups) with a diacid ( a molecule with two ............................... groups).
Nylon is an example of a polyamide. One version of nylon can be made by reacting
1,6-diaminohexane with hexane-1,6-dioic acid.
Complete the diagram to show part of the nylon polymer formed when these 4 molecules react.
Once drawn, circle the amide links in the polymer
O
H
H
N
H
O
H
H
C
C
H
H
C
H
H
H
C
C
C
C
H
H
H
H
H
H
C
N
O
H
H
C
C
C
C
H
H
H
O
O
H
H
H
O
H
C
N
H
O
H
C
H
H
H
H
H
C
C
C
C
C
O
H
H
N
H
H
H
H
O
H
C
C
C
C
H
H
H
H
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C
O
H
H
H
H
H
H
C
C
C
C
C
C
H
H
H
H
H
H
H
C
H
H
H
H
C
C
C
C
H
H
H
H
O
C
N
O
H
H
H
O
H
H
O
H
Section (e) Natural products.
(i) Carbohydrates
1. Photosynthesis is the process by which ........................................... make carbohydrates from .............................
............................................. and ......................................... The process uses ........................... energy from the Sun.
The catalyst for the reaction is the green pigment called .............................................. . During photosynthesis
the plants release the gas ............................................ into the atmosphere.
Balance the photosynthesis reaction shown below
................CO2
+ ..................H2O
carbon dioxide
water
C6H12O6 + ..........O2
glucose
oxygen
2. Respiration is the process by which animals and plants obtain ............................. by breaking down
carbohydrates. The carbohydrate burns in oxygen giving out energy and the waste products
...................................... ............................... and .................................
The respiration reaction is the exact ....................................... of the photosynthesis reaction.
3. Carbohydrates contain the elements ......................................., ......................................................... and ..........................
Carbohydrates are divided into sugars and starches. Examples of sugars include glucose, .................................
........................................... and .................................................
4. Iodine solution is used as the test for ........................................ . When added to ........................................
iodine solution changes colour from red/brown to ..........................................................
5. Benedict’s solution is used as the test for most sugars. When heated with Benedict’s solution
glucose, fructose and maltose change the colour of the Benedict’s solution from blue to ....................................................... Sucrose is a exception and does not react with ............................................... solution.
6. In a plant glucose monomer molecules are joined together with a loss of water to form the polysaccharide
........................................... . This type of polymerisation is called .................................................... polymerisation.
7. During ......................................... large starch molecules break down by reacting with ..................................
to form glucose. This is an example of a ....................................... as it involves the breakdown of a molecule
by reacting it with water.
The small glucose molecules can pass through the walls of the ........................ intestine into the bloodstream.
In the body it is the enzyme, ......................................, found it saliva and ......................................................... acid
in the stomach that brings about the hydrolysis of starch into glucose.
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(ii) Proteins.
1. Proteins are condensation polymers made by combining together many ......................... ...........................
monomer molecules.
2. Proteins are required by the body for ........................ and tissue ...................................
3. Proteins and amino acids contain the elements carbon, hydrogen, oxygen and ......................................
4. The body cannot make all the amino acids required to make body proteins. The supply of these
.............................................. amino acids depends on the diet we eat.
5. Shown below is a small part of a protein polymer chain
H
H
C
H
O
H
N
H
N
H
H
C
H
C
C
H
C
O
O
H
N
C
H
C
H
N
H
H
Circle the peptide (amide) links shown in this part of the protein molecule.
Draw the extended structural formula of the two amino acids produced by the hydrolysis of
this part of the protein molecule.
6. Proteins form many of the bodies major structural units such as muscles and tendons. Proteins also form
many of the enzymes and hormones in the body. For example haemoglobin in .................. blood cells and insulin
are both proteins.
(iii) Fats and Oils
1. Fats and oils are naturally occurring esters. Fats and oils can be classified according to their origin
– animal, ......................... or ......................................
2. Oils have ........................................... melting points than fats. The ....................................... melting points
of oils is due to the oils being ............................................................. molecules. The fact that oils are
..................................................... can be shown by the fact that oils quickly decolourise .............................
solution.
3. Fat molecules are more linear in shape than oil molecules. This means that fat molecules can pack
together .................... closely than the more angular oil molecules. Since the fat molecules can pack
together more closely than oil molecules the van der Waals forces between fat molecules are
..................................... than between oil molecules.
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4. The conversion of unsaturated oils into solid fats in margarine manufacture involves the addition
of ......................................... (hydrogenation) across some of the double bonds in the oil molecules.
5. Fats and oils are a ....................... concentrated source of energy in the body than carbohydrates.
6. The hydrolysis of a fat (or oil) produces a mixture of ...................................... (propane-1,2,3-triol) and
............................. acids (long chain carboxylic acids) in the ratio of one molecule of ........................................... to
three molecules of fatty acid.
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Unit 3
Section (a) – Acids and Bases
1. The pH of pure water and other neutral solutions is .........................
The pH scale measures how acidic or ........................................... a solution is.
The pH scale goes from 0 to .............
Solutions with a pH value of .................. than 7 are acidic. Solutions with a pH value of ...................... than 7
are alkaline.
Soluble metal oxides form ........................................... solutions when they dissolve in water.
Soluble non-metal oxides form ................................. solutions when they dissolve in water.
e.g.
Substance
pH when dissolved in water
calcium oxide
greater than 7 (alkali)
sulphur dioxide
lithium oxide
carbon dioxide
nitrogen dioxide
sodium oxide
2. All acid solutions contain more ................................... (H +) ions than ........................................... (OH -) ions.
Acid solutions form ................................. gas at the negative electrode when they are electrolysed – this
shows that acid solutions contain the ............................................... ion.
Hydrogen gas burns with a ............................... – this is the test for hydrogen.
3. Metal oxides and metal hydroxides that dissolve in water form ........................................ solution.
It is the metals in groups 1 and 2 of the Periodic Table that form soluble oxides.
So sodium oxide, ................................ oxide, lithium hydroxide, ..................................... hydroxide form alkali
solutions when dissolved in water.
Alkali solutions contain more ...................................... (OH -) ions than ...................................... (H -) ions.
4. In water, and aqueous solutions, there is an .............................................. between hydrogen ions,
hydroxide ions and water molecules.
H2O(l)
H+(aq) + OH --(aq)
The equilibrium lies far to the ............................... ie most of the water exists as ...................................
5. At equilibrium the concentrations of the reactants and products remains ..........................................
It is important to realise that at equilibrium the concentrations of reactants and products will
not usually be .....................................
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6. You should be able to use the relationship shown below
n
C
V (litres)
to calculate
(a) The number of moles of potassium hydroxide present in 200 cm 3 of 0.5 mol/l potassium
hydroxide solution.
(b) What is the concentration of a hydrochloric acid solution that contains 0.1 moles of hydrochloric
acid in 200ml of solution?
7. In aqueous solution strong acids are .................................... ionised. Weak acids are only ........................
ionised. Hydrochloric and sulphuric acids are .............................. acids. Ethanoic acid is a ..................... acid.
8. When equimolar (same concentration) solutions of a strong acid and a weak acid are compared the
strong acid has a ................................. pH, a ...................................... conductivity and a ................................
reaction with magnesium than the weak acid.
9. In aqueous solutions strong bases are ................................ ionised. Weak bases are only ........................
ionised. Sodium hydroxide and potassium hydroxide are .............................. bases. Ammonia is a .................
base
11. When equimolar (same concentration) solutions of a strong base and a weak base are compared the
strong base has a ................................. pH, and a ...................................... conductivity.
12. A neutralisation reaction occurs when an .............................solution and an ........................................ solution
cancel each other out. When an acid solution reacts with an alkali solution a ............................ and water
are formed.
13. Complete the table below which shows some everyday substances that can be used as neutralisers.
Substance
Milk of magnesia
What it is used to neutralise
Acid indigestion
Baking Soda
Vinegar
Lime
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14. Underline the substances below which will neutralise an acid solution.
copper,
copper sulphate,
sodium carbonate,
zinc,
magnesium oxide,
bromine solution,
silicon,
sodium nitrate,
lithium hydroxide,
water
15. Metal oxides, metal hydroxides, metal carbonates and MAZIT metals are all substances which will
neutralise .................................... . We call substances which neutralise ................................. bases.
16. The MAZIT metals are magnesium, ........................................, ........................................, ........................................,
and .........................................
When a MAZIT metal reacts with an acid solution the gas ........................................ is given off and
a salt is formed.
17. When a carbonate (or hydrogen-carbonate) reacts with an acid the gas ................................. ..................................
is given off and a salt and water are formed.
Carbon dioxide gas turns ............................. ...................................... chalky. This is the test for carbon dioxide.
18. Hydrochloric acid (HCl(aq)) forms salts called ........................................ .
Sulphuric acid (H2SO4(aq)) forms salts called ........................................ .
Nitric acid (HNO3)forms salts called .........................................
19. Complete the following word equations:(a) Sodium hydroxide + nitric
........................................ ........................................ +........................................
(b) Potassium carbonate + sulphuric acid
potassium sulphate + ........................... .......................... + water
(c) Magnesium + ........................................ acid
magnesium chloride + ........................................
20. The following is an example of a neutralisation reaction.
NaOH + HCl
NaCl + H2O
If 30 ml of sodium hydroxide is neutralised using 40ml of 0.25 mol/l hydrochloric acid, calculate
the concentration of the sodium hydroxide solution.
Method of calculation:C x V x P(acid)
=
[P(acid) = No. of H+ ions from acid
C x V x P (alkali)
P(alkali) = No. of OH- ions from alkali)
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21. What volume of 0.1 mol/l sulphuric acid (H2SO4) is required to neutralise 40ml of 0.2 mol/l
potassium hydroxide (KOH)?
22. A table of solubilities is found in the data booklet on page ....................... A precipitation reaction occurs
when an insoluble ................................... is formed when two solutions are mixed.
Name the precipitate formed in each of the following reactions.
(a) copper sulphate + sodium carbonate
................................................................
(b) lead nitrate + sodium iodide
..................................................................
23. Describe how solid copper sulphate can be formed from copper carbonate and sulphuric acid.
(b) Metals
1. Electricity is a flow of charged particles. The particles flowing through metal wires are ..............................
The charged particles flowing through an ionic solution are ...........................
Electricity is produced by a ..................................... reaction in a cell. When the chemicals in the cell are
................................. ...................... the cell may have to be replaced by a new one.
Some types of cells such as lead/acid and nickel/cadmium can be ..................................................
2. An electrochemical cell is formed when two ...................................... metals are placed in a conducting solution
called an ................................................. The bigger the gap between two metals in the electrochemical
series (page 7 of data booklet) the ....................................... the voltage of the cell. Electrons always
flow from the metal ................................... in the electrochemical series to the one ...................................... in the
series.
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3. Use these words to label the diagram of a zinc/copper cell.
ion bridge
solution of Cu2+(aq) ions
zinc electrode
electron flow
solution of Zn2+(aq) ions
copper electrode
The ion bridge complete the circuit by allowing a flow of ............................ between the two beakers.
4. When a chemical loses electrons the reaction is called ...........................................................
When a chemical gains electrons the reaction is called ..........................................................
In the cell shown above the ion electron equations can be written for the oxidation and reduction reactions
by using the electrochemical series on page 7 of the data booklet.
Of the two metals copper is ..................................... down in the electrochemical series.
This reaction stays as written ie as
Cu2+aq)
+
.......................
.........................
This is the ............................................... reaction
The zinc is ............................ up in the electrochemical series. The ion-electron equation on page 7 is
reversed ie
Zn(s)
.............. + ................. This is the ............................................... reaction.
5. When a metal ...................... in the electrochemical series is added to a solution containing ions of
a metal lower down in the electrochemical series a .................................................... reaction occurs.
e.g.
Zn(s) +
Cu2+SO42-(aq)
...................(s) + ................................(aq)
The sulphate ions are not changed in any way in this reaction – they are called the ..........................................
ions.
In this reaction the zinc is oxidised and the copper(II) ions are ..............................................
As the reaction has both reduction and oxidation taking place it is called a ................................. reaction
6. Metals conduct electricity when ............................ or molten. Other properties of metals include
good conductivity of ................................., strength, easily shaped (..........................................) and ductility.
The supply of metals is ...................................... and so they are recycled to make supplies last longer.
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7. Metals react with oxygen to form metal ........................................... The more reactive the metal, the
more energy is ................................. ....................... in the reaction. Very reactive metals such as the
..................................... metals in group ......... are stored under oil to stop them reacting with oxygen in air.
8. Some very reactive metals react with water. These are the .............................. metals in group ........
of the periodic table. When an alkali metal reacts with water the products of the reaction are
.................................................. gas and an ..................................... solution of the metal hydroxide.
9. The MAZIT metals are the metals Magnesium, ..........................................., .............................., .........................
and ......................... . The MAZIT metals react with acid solutions to form a .................................. and
........................................ gas.
Metals lower than hydrogen in the electrochemical series such as ........................ and ...........................
do not react with acid solutions.
10. A rock which contains sufficient metal to make it worthwhile extracting the metal is called an .............
Some very unreactive metals such as ..................................... and .................................... can be found as the
pure metal in the Earth’s crust.
Unreactive metals such as mercury can be obtained from their ores by ........................ alone.
11. The metals from zinc to copper in the electrochemical series can be extracted from their ores
by mixing the ore with ........................................... and then strongly heating the mixture.
12. The most reactive metals including ............................................ are obtained from their ores using electricity.
13. Iron is produced from iron ore in a .................................. furnace. The key reactions which take place
are:C + O2
->
.........................
production of carbon dioxide
C + CO2 -> 2.......................
production of carbon monoxide
Fe2O3 + 3CO
production of iron and carbon dioxide
-> 2............ + 3 ..............
14. Corrosion is a .............................. reaction that occurs on the ................................. of a metal changing it from an
element into a compound. Different metals corrode at ............................................ rates.
Corrosion of iron is also known as ........................................... . Both ................................ and ....................................
(from air) are needed for rusting. Rusting occurs much faster if there is an electrolyte such as .....................
solution present.
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15. When iron rusts the iron atoms ...................... two electrons to form Fe 2+(aq) ions. This is an example of
an oxidation reaction.
The electrons that are lost by the iron atoms are gained by the ......................................... and .................................
molecules to form hydroxide ions.
Complete these ion electrons equations for these reactions (use page 7 of the data booklet to help you)
Fe(s)
............... + ...............
2H2O(l) + O2 (g) + 4e-
...............
16. Ferroxyl indicator can be used to show the extent of the rusting process. Ferroxyl indicator turns
………………………………….in the presence of iron(II) ions. Ferroxyl indicator turns ....................... in the presence
of hydroxide ions.
17. Salt spread on roads to keep them free of winter ice dissolves in water to form an ........................................
solution which speeds up the rate of corrosion of car bodies.
18. A surface barrier which stops ................... and ........................... getting to the surface will prevent iron rusting.
Paint, ..........................., ............................. and ................................. can all be used to cover the iron with a
protective outer coating.
In electroplating, ................................................. is used to cover the surface of iron with a layer of another
metal e.g. in nickel plating the iron is covered with a protective layer of ..................................................
Galvanising involves covering iron with a protective layer of ...............................................
In tin-plating, ................................. containers are given a thin layer of tin to protect the iron underneath from
rusting.
17. Iron will not rust if electrons are ......................................... onto the iron.
In sacrificial protection iron is connected to a more reactive metal such as ...................................... or ..................
During sacrificial protection, ......................................... flow from the metal higher in the electrochemical
series onto the iron, stopping the iron rusting.
By connecting iron to the ............................................ terminal of a battery, electrons will be pushed onto the
iron, stopping it rusting.
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