Download Honors Chemistry

CP Chemistry
Mid-Term Exam Review Sheet - 2015
I.
Vocabulary
Chemistry
matter
units
metric system
length / meter
mass / kilogram
time / second
volume
density
chemical property
physical property
malleability
ductility
conductivity
reactivity
phase
state
solid
liquid
gas
melting / freezing
evaporating / condensing
mixture
solution
substance
homogeneous
heterogeneous
element
compound
atom
molecule
formula unit
diatomic elements
nucleus
isotope
energy
frequency
wavelength
light
electromagnetic waves
photons
quantized
subatomic
charge
neutron
proton
electron
ion
cation
anion
polyatomic
symbol
atomic number
atomic mass
mass number
radiation
radioactivity
stable
background radiation
nuclide
decay
emission
, , and 
bombardment
half-life
fission
chain reaction
nuclear fission reactor
reaction vessel
fuel rods
control rods
fusion
nuclear fusion reactor
radioisotopes
tracers
quantum numbers
n, l, m, s
energy level
orbital
shape
orientation
spin
electron configuration
triads
octaves
period
metal
non-metal
metalloid
group / family
period
alkali metals
earth alkali metals
transition metals
rare earth metals
halogens
noble gases
subscript
formula
element
compound
ionic
covalent
hydrocarbon
isoelectronic
atomic radius
ionic radius
electronegativity
mole
Avogadro’s number
molar mass
percent composition
hydrate
reaction
equation
law of conservation of
mass and energy
system
surroundings
reactant
product
yield
aqueous
synthesis
combustion
decomposition
dissociation
dissolve
single displacement
activity series
double displacement
solubility
precipitate
net ionic equation
spectator ions
mole ratio
stoichiometry
II. Lists
Greek Prefixes for the Metric System
Prefix
Abbreviation
Factor
megakilodecicentimillimicronanopico-
M
K
d
c
m

n
p
106
103
10-1
10-2
10-3
10-6
10-9
10-12
Polyatomic Ions - (see sheet)
Greek Prefixes for covalent compounds
Prefix
Number
monoditritetrapentahexaheptaoctanonadeca-
One
Two
Three
Four
Five
Six
Seven
Eight
Nine
Ten
Prefix
Number
methethpropbutpenthexheptoctnondec-
One
Two
Three
Four
Five
Six
Seven
Eight
Nine
Ten
Prefixes for hydrocarbons
People
Atomic Theory
Democritus
Dalton
Thomson
Rutherford
Chadwick
Bohr
Atomic Models
solid sphere model
plum pudding model
nuclear / planetary model
revised planetary model
Bohr atom
modern atom
Periodic Table
Dobereiner
Newlands
Mendeleev
Moseley
Ramsay
III. Problems
A. Mathematics
1.
Scientific Notation
exponents:
positive exponent - move decimal to the right
eg. 3.78x104 = 37,800
negative exponent - move decimal to the left
eg. 3.78x10-4 = 0.000378
operations:
addition and subtraction - exponents must be the same; keep exponent
eg. 1.2x105 + 3.4x105 = 4.6x105
multiplication - add exponents
eg. (6.0x107)(8.0x109) = 48x1016
division - subtract exponents
eg. 3.6x109 / 1.2x104 = 3.0x105
Sample Problems
1. Convert to or from scientific notation.
a. 0.00003 =
b.
65,000 =
d.
0.0017x109 =
Calculate.
a. 6.5x102 + 2.0x103 =
b.
7.8x105 - 5.5x104 =
(4.0x10-2)(3.0x104) =
d.
12x10-6 / 4x102 =
c.
c.
2.
480x10-2 =
Units
addition and subtraction - units must be the same
eg. 1.2x105 dm + 3.4x106 cm =
1.2x106 cm + 3.4x106 cm = 4.6x106 cm
multiplication and division - units do not have to be the same but they may cancel
eg. (7.8x10-14 s-1)(9.0x108 J.s) = 70x10-6 J
Sample Problems
4.8x10-3 L + 3.7x101 mL =
(80 km/hour)(4 hours) =
B. Symbols
atomic number - number of protons (and number of electrons in a neutral atom)
the atomic number is the “fingerprint” of an element
atomic mass - mass of a mole of atoms of an element (weighted to include isotopes)
mass number - number of protons and neutrons in the nucleus
isotopes - atoms of the same element with different numbers of neutrons
(and different mass numbers)
mass number
40
atomic number
20
symbol:
Ca
atomic symbol:
Ca-40
- the symbol for the element
just the symbol for the element and the mass number
use the periodic table to find the atomic number
Sample Problem
How many protons, neutrons and electrons are in Cu-64? Write the symbol for this isotope of
copper.
C. Nuclear Chemistry
1.
Balancing nuclear equations
a. balance mass number and atomic number separately
b. assign element symbol
eg.
238
U  4He + 234Th
2.
Half-life
amount of sample remaining after n half-lives = (1/2)n
eg. How many grams of a 1.5-mol sample of Mo-91 remain after one hour and 2 minutes if the
half-life of Mo-91 is 15.5 minutes?
Amount of sample remaining = (1/2)4 (1.5 moles) (91 grams/mol) = 8.5 grams Mo-91
Sample Problems
1. Balance the following and label the parent, daughter, and particle emitted or absorbed.
a.
0
227
_____ 
e +
Ac
-1
b.
27
1
n 
Al +
13
c.
27
4
Al +
13
_____
0
He 
2
1
_____ +
n
0
2.
How many moles of a 125-gram sample of Cl-39 remain after 166.5 minutes if the half-life of
Cl-39 is 55.5 minutes?
D. Electrons
1. Quantum Numbers
n = Principal Quantum Number - energy level
l = orbital (shape)
l=0 s
1 p
2d
3f
m = orientation
for p orbitals, x, y, and z
for d orbitals, x2-y2, xz, yz, xy, and z2
for f orbitals, x(y2-z2), y(x2-z2), z(x2-y2), etc.
s = spin
Eg. For an electron in the n = 4 energy level,
l=
0 or s
1 or p
2 or d
m=
0
-1, 0, +1 -2, -1, 0, +1, +2
s = +1/2 and -1/2 for each m
2. Symbolism
n=1
l = 0  (n-1)
m = -l…0…+l
s = +1/2 or -1/2
3 or f
-3, -2, -1, 0, +1, +2, +3
nlm
eg. For an electron with the quantum numbers n = 2, l =1, m = +1, s = +1/2,
the symbol would be 2px or 2py or 2pz.
For an electron with the quantum numbers n =2, l=1, m = -1, s = +1/2
the symbol would be 2px or 2py or 2pz but different from the previous symbol.
Sample Problems
What are all of the possible sets of quantum numbers for electrons in the n = 3 energy level?
Write the symbol for an electron with the quantum numbers n = 3, l = 2, m = -2, s = +1/2.
Write the symbol for an electron with the quantum numbers n = 3, l = 2, m = -1, s = +1/2.
Write the symbol for an electron with the quantum numbers n = 3, l = 2, m = -1, s = -1/2.
E. Periodic Trends
atomic radius - increases down and to the left
ionic radius - depends on whether the ion is positive or negative
same number of protons, the positive ion is smaller
same number of electrons, the positive ion is smaller
electronegativity - increases up and to the right (noble gases = 0)
Sample Problems
Write the following in increasing order
atomic radius : Al, Cl, P
ionic radius : Br-, Kr, Se-2
F.
electronegativity: F, N, O
Chemical Formulas
1.
Be, Ca, Mg
Br-, Cl-, FK, Na, Rb
Writing formulae
a.
Ionic Compounds
monatomic ions:
Group 1 : +1
Group 2 : +2
Group 3 : +3
Group 15 : -3
Group 16 : -2
Group 17 : -1
transition metals : use ion sheet or use Roman numerals
polyatomic ions : use ion sheet
Opposites attract : the positive or more metallic ion goes first when writing the formula
The farther to the left on the periodic table, the more metallic.
When writing a compound’s formula, write the ions’ symbols with the charge.
If the charges add up to zero, then just put the symbols together to form the formula.
If the charges do not add up to zero, switch the charges and reduce.
Example: Make a compound from acetate and calcium. Calcium goes first because
calcium is positive.
+2 + -1 = 1
since 1 does not equal 0, switch the charges…
Ca(C2H3O2) 2
!!!
(use parentheses for polyatomic ions)
b. Transition metals
The Roman numeral indicates the charge on the metal.
Example: cerium (IV) sulfate
Ce+4 SO4-2 so 2 sulfate ions are needed to cancel the charge on cerium
 Ce(SO4)2
c. Covalent compounds
Use prefixes to determine the number of atoms of each element.
Example: silicon tetrafluoride
No prefix means one atom of silicon and tetra- means 4 atoms of fluorine.
 SiF4
d. Hydrocarbons
Use the prefix to find the number of carbon atoms. Use the suffix to calculate the number
of hydrogen atoms.
-ane : 2n+2
-ene : 2n
-yne : 2n-2
Example: propyne
prop- means 3 carbon atoms, -yne means double the carbons and add 2.
 C3H4
2.
Naming Compounds
a. Ionic: Metal + Non-metal / polyatomic
The name of the metal comes first. Do not change the name.
The name of the non-metal goes last.
If the non-metal is monatomic, change the ending to “-ide”.
If the non-metal is polyatomic, just use its name.
Eg. CaCl2 - calcium chloride
the metal is calcium so it keeps its name
the non-metal, chlorine, is monatomic, so it changes its ending to “-ide”
b. Transition metals
These are the ones that are on the polyatomic ion sheet and have weird names.
The same rules go for the non-metal ( “-ide” or stay the same)
The metal can either be the weird name that goes with the charge
or
The metal can keep its element name and simply take Roman numerals
indicating its charge.
Eg. FeCrO4
CrO4 is chromate.
Fe can be ferrous (if its +2) or ferric (if its +3). CrO 4 has a charge of -2.
No subscripts, so Fe must be +2  ferrous chromate or iron (II) chromate
c. Covalent: Non-metal + Non-metal
The more metallic element (closest to the metal/non-metal line) goes first.
The first non-metal keeps its name.
The non-metal changes its ending to “-ide”.
Add a Greek prefix to both to indicate how many atoms of each element are used.
(drop mono- if there is only one atom of the first non-metal)
Eg. NO2 - nitrogen and oxygen.
Nitrogen is more metallic so it goes first.
Oxygen becomes oxide.
One nitrogen and two oxygens.
mononitrogen dioxide - drop the mono that comes first  nitrogen dioxide
d. Hydrocarbons
The prefix comes from the number of carbon atoms.
The suffix comes from number of hydrogens compared to the carbon atoms.
Eg. C5H12
pent- is the prefix used for 5 carbons.
-ane is the suffix when the number of hydrogens is double the number of carbons plus 2
 pentane
Sample Problems
Name the following compounds.
a. KI
b.
SO3
c. PbSO4
d.
HBr
e. C6H10
f.
BaS
Write the formulae for the following compounds.
a. ammonium sulfide
b. dinitrogen monoxide
c. tin (II) nitrate
d. butyne
e. chromium cyanide
f.
ferrous carbonate
G. Moles
1.
avogdro’s Number - NA - the number of particles in one mole of a substance
1 mole = 6.02x1023 atoms, molecules, or formula units
2.
molar mass - atomic mass on the periodic table gives you the mass (in grams) per 1 mole!
Eg. Na2CO3
3.

2 Na = 46 g
C = 12 g
3O = 48 g
106 g Na2CO3
1 mole Na2CO3
percent composition - add up the total molar mass of the compound.
Then take the mass of each element divided by the total mass times 100.
Sample Problems
1. How many moles are in 1.3x1024 atoms of Mg?
2. What is the mass of 3.8 moles Ba(NO3)2?
3. What is the percent composition of NaHCO3?
H. Reactions and Equations
1.
law of conservation of matter
Equations must be balanced!
2.
5 types of reactions:
A + B  AB
more than one reactant  one product
Eg. 2K + Cl2  2KCl
a. synthesis
2A + O2  2AO
synthesis with oxygen as one of the reactants
Eg. 2Na + O2  2NaO
b. combustion
c. decomposition AB 
A + B
one reactant breaks into more than one product
Eg. H2CO3  CO2 + H2O
d. single displacement
A + BC  AC + B
an element plus a compound yields an element and a compound
Careful! Check your activity series. The reactant that is an element must be
stronger than the ion it’s replacing!
eg. Cu + 2AgNO3  Cu(NO3)2 + 2Ag
2Ag + Cu(NO3)2  No Reaction!
e. double displacement AB + CD  AD + CB
two compounds react to form two compounds
Remember that a compound is made of a positive and a negative!
Look for a precipitate on the products side.
eg. H2SO4 + BaCl2  BaSO4 (pr) + 2HCl
dissociation
AB  A+ + Bone reactant dissolves in water into its ions
eg. NaCl  Na+ + Clnet ionic equation
eg. Calcium acetate reacts with potassium sulfate.
1.
Write the overall equation.
Ca(C2H3O2)2 + K2SO4 ----> 2KC2H3O2 + CaSO4
2.
Write soluble compounds in ionic form.
Ca+2 + 2C2H3O2- + 2K+ + SO4-2 ----> 2K+ + 2C2H3O2- + CaSO4
3.
Cancel species that appear on both sides.
Ca+2 + 2C2H3O2- + 2K+ + SO4-2 ----> 2K+ + 2C2H3O2- + CaSO4
4.
Write the resulting equation.
Ca+2 + SO4-2 ----> CaSO4
Sample Problems
Balance and classify the following reactions:
a. AgNO3 +
KCl 
KNO3 +
b.
Al +
O2 
Al2O3
c.
Sn +
Cl2 
SnCl4
d.
Mg(OH)2 
e.
Fe +
f.
H3PO4 
Mg+2
+
Cu(C2H3O2)2 
P2O5 +
AgCl
OH-1
Fe(C2H3O2)2 +
H2O
Write the net ionic equation for the following equation.
Iron (III) bromide reacts with ammonium sulfide.
Cu
I.
Stoichiometry
Write the balanced equation.
Start with what you are given.
Always go through moles and the mole ratio!
Don’t stop until you find what you were looking for.
Sample Problems
Copper (II) sulfate reacts with sodium sulfide to produce copper (II) sulfide and sodium sulfate.
a. How many moles of sodium sulfate are formed from 0.3 moles of sodium sulfide?
b. How many grams of copper (II) sulfate are needed to react with 20.3 grams of sodium sulfide?