Download Lesson x- Review W14 answers

Name: _______________
Date: __________________
SNC 1D Chemistry Unit Review
For a list of the topics you are responsible for, see the Chemistry Learning Goals and Success
Criteria sheet. In addition, include that you need to have the understanding of independent,
dependent, and controlled variables for scientific experiments.
Practice Questions
1) Go to HCtoday.ca.  Academics  Teacher Pages  K.Waller  SCIENCE SNC1D 
SNC1D Notes Spring 2014  1-Chemistry  Day x- Chemistry Practice Multiple Choice
2) Describe the following models of the atom: Dalton, Thompson, Rutherford, and Bohr. Also
specify what each scientist contributed to the model.
Dalton
- atoms are small indestructible spheres of matter like billard balls
-discovered atoms of different elements are different
Thompson
- atoms have a positively charge ‘dough’ with electrons placed throughout like raisins in plum
pudding
-discovered charge in the atom
Rutherford
-atoms are mostly empty space (where electrons are) with a dense positive centre (nucleus)
-used the gold foil experiment to discover the nucleus; most particles went through, few bounced
back
Bohr
-atoms have a dense nucleus surround by shells (energy levels) of electrons
-discovered electrons with certain energy jump from one shell to another
3) Describe the location, mass, and charge of an electron, neutron, and proton.
4) Give the group number (and name if known), atomic mass, atomic number, symbol, and state
if it is a metal or non-metal for the following elements: cesium, silicon, argon, bromine
Element
Atomic mass
Atomic number
Symbol
Metal/
Non-metal
Cesium
132.9
55
Cs
Metal
Silicon
28.09
14
Si
Metalloid
Argon
39.95
18
Ar
Non-metal
35
Br
Non-metal
Bromine
79.90
5) Fill in the following table..
Symbol
Element name
Atomic
number
Atomic
mass
# of
protons
# of
neutrons
# of
electron
s
K
potassium
19
39.10
19
39-19=20
19
Solid,
liquid
or gas
s
Be
beryllium
4
9
4
9-4=5
4
s
S
sulfur
16
32.07
16
32-16=16
16
s
Br
bromine
35
79.90
35
80-35=45
35
l
O
oxygen
8
16.00
8
16-8=8
8
g
Li
Lithium
3
6.94
3
7-3=4
3
s
O
oxygen
8
16.00
8
16-8=8
8
g
6) Draw the Bohr-Rutherford diagrams of Be, Si, and O.
Beryllium
Silicon
Oxygen
7) Describe the pattern of electron arrangement across a period and down a group.
Across a period- one valence electron is added as you move from left to right
Down a group- one shell is added as you go down each group, but the number of valence
electrons remains the same
8) What is the trend in reactivity of the alkali metals (which is the most reactive, the least)?
As you go down the alkali metal group the elements get more reactive.
9) Explain the underlying reason for the trend.
This trend occurs because as you go down the group the number of shells increases,
increasing the distance between the positive nucleus and the single valence electron. As the
valence electron and the nucleus get further apart the attraction between them decreases
making the valence electron easier to remove (more reactive).
10) Describe the five components of the particle theory of matter.
11) What is the difference between an element and a compound?
Compounds contain two or more different elements bonded together.
Elements are composed of one type of atom. Elements can exist as atoms or molecules.
12) What is the difference between an atom and a molecule?
An atom is the smallest component of an element having the same properties as the element. A molecule is
formed when two or more atoms are bonded together.
13) What is the difference between a pure substance and a mixture?
Pure substances have only one kind of atom or molecule. A mixture has more than one type of
pure substance mixed together.
14) For each of the following state which of the following words apply (atom, molecule, element
compound, pure substance, mixture). Explain why they apply:
a) lemonade
d) NaCl (table salt)
g) C6H12O6
b) carbon
e) Fe
h) chalk (CaCO3)
c) H2 gas
f) air
lemonade
mixture
Carbon
Atoms of an element, pure substance
H2 gas
Molecules of an element, pure substance
NaCl
Compound, pure substance
Fe
Atoms of an element, pure substance
Air
Mixture of atoms and molecules
C6H12O6
Compound, pure substance
chalk
Compound, pure substance
8) For the following compounds state which atoms are present and how many for each:
i) Na2SO4
Na2SO4
ii) C2H4
iii) CoCl2
2 sodium
1 sulfur
4 oxygen
C2H4
2 carbon
4 hydrogen
CoCl2
1 cobalt
2 chlorine
CaCO3
1 calcium
1 carbon
3 oxygen
iv) CaCO3
9) Define the terms physical and chemical property.
10) What are 8 physical properties that can used to describe matter.
11) What is the difference between lustre, malleability, and ductility?
Lustre describes how easily light is reflected off a substance, malleability describes the ability of
a substance to be hammered into sheets, and ductility describes a solid’s ability to be stretched
into a wire.
12) Give three qualitative and three quantitative properties of your pencil.
Qualitative- solid, opaque graphite centre is dark grey, slightly lusterous and conducts
electricity.
Quantitative- 7 cm in length, 5 mm diameter, graphie has a density of 2.09g/cm3
13) Give three physical and one chemical property of gasoline.
Physical- transparent, yellow, non-viscous liquid
Chemical- combusts easily
14) What are the three density formulas?
D=m/V
V=m/D
m=DV
15) What are two possible units for density?
g/mL
g/cm3 kg/L
16) What is the formula for the volume of a rectangular block?
V= length x width x height
17) Use the GRASP method to solve for the following.
a) The mass of a regulation golf ball is 45.9 g. If it’s volume if 38.8 mL, what is its
density? Will it sink or float? Explain why.
Given
m = 45.9 g
V = 38.8 mL
Required
D= ?
Analysis
Find the density using D = m/V then compare it to the density of water (1 g/mL).
If the density is greater than it will sink, if it is less, the golf ball will float.
Solution
D = m = 45.9 g = 1.18 g/mL
V 38.8 mL
Summary
The density of the golf ball is 1.18 g/mL which is higher than the density of water so the golf ball
will sink when put in water.
b) A block of wood has a density of 0.89 g/cm3. If its length, width, and height are 8.9
cm, 3.4 cm, and 2.3 cm, respectively, what is its mass?
Given
l= 8.9 cm
w= 3.4 cm
h= 2.3 cm
D= 0.89 g/cm3
Required
m=?
Analysis
Find the volume of the block of wood using V=lxwxh then use m=DV to find the mass
Solution
V= l x w x h
= 8.9 cm x 3.4 cm x 2.3 cm
= 70 cm3
m = DV
= (0.089g/cm3)( 70 cm3)
= 6.19 g
Summary
The mass of the block of wood was 6.19 g.
20) A gas is tested to be either hydrogen, oxygen, or carbon dioxide. What evidence would you
look for to identify which of the three it may be?
Hydrogen- burning splint gives a ‘pop’ sound
Oxygen- glowing splint is reignited
Carbon Dioxide- burning splint or candle is smothered (flame goes out)
21) A student runs an experiment testing the effect of different amounts of salt on the boiling
point temperature of water. In pot A she adds no salt (NaCl) to the water, in pot B she adds
20 g of NaCl, and in pot C she adds 40 g of NaCl. She boils each and finds that pot A boiled
at 100 °C, pot B boiled at 102 °C, and pot C boiled at 104 °C. Identify the dependant
variable, the independent variable, and 2 controlled variables.
Independent variable- amount of salt is changed
Dependent variable- boiling point temperature is measured
Controlled variables- the type of salt (NaCl), the size of the pot, the amount of water, the type
of pot, the stove element and temperature etc. should all be kept constant