Science 10 Chemistry Unit Review
Chemistry Chapters 4, 5, 6, 7
Chapter 4
1) What are the trends in the periodic table (metals,
nonmetals, noble gases, etc.)?
A: -Metals on the left; nonmetals on the right
2) What is the difference between ionic and covalent compounds? (give examples of each)
A: Ionic: metal + nonmetal,
eg. NaCl
Covalent: nonmetal + nonmetal
eg. CO2
3) Where on the periodic table is the atomic # of an element found? What does that represent?
A: Top left hand corner.
Represents # of protons
4) What is the atomic # of Magnesium? How many protons does an atom of Magnesium have?
A: atomic #12, 12 protons
5) What are valence electrons?
A: Outermost electrons
6) What is the difference between a Bohr diagram and a Lewis diagram?
A: Bohr: Shows all shells with all electrons
Lewis: Shows valence electrons only
7) Draw a Bohr diagram for each of the following atoms: Calcium and Chlorine.
8) Draw a Lewis diagram for each of the following atoms: Calcium and Clorine.
9) What is an ion?
A: an atom that has lost or gained electrons
10) Draw a Bohr and Lewis diagrams for Mg+2, P-3, O-2
Science 10 Chemistry Unit Review
11) Draw a Lewis diagram for Calcium Chloride (CaCl2) and Magnesium Oxide (MgO)
12) Draw a Lewis diagram for O2, HF, Cl2, NaCl
13) What are the naming rules for ionic compounds? (remember multivalent metals and polyatomic
ions)
A: -ending in ide
-multivalent metals → use roman numerals to specify charge
-polyatomic ions → use name of ion from data booklet (usually end in ite or ate)
14) What is a multivalent metal? (give an example)
A: metals with multiple ion charges (eg. Cu +2 or +1)
15) What is a polyatomic ion? (give an example)
A: compound that has a charge
eg. Phosphate PO4-3, ammonium NH4+ Sulphate SO4-2, Sulphite SO3-2
16) What is the law of conservations of mass?
A: states that mass is conserved in a chemical reaction
*the total mass of the products = total mass of reactants
17) Why do you need to count atoms when balancing equations?
A: in a chemical reaction, the atoms have to be equal on either side of the equation
18) Count the number of each type of atom in the following compounds: H2SO4, C6 H12O6
A: H2SO4 = 2H, 1S, 4O; C6 H12O6 = 6C, 12H, 6O
19) a) Name the three subatomic particles
A: proton, electron, neutron
b) State the electric charge of each
A: +1, -1, 0
c) State the location of each within an atom
A: p + n in the nucleus. Electrons surround the nucleus in a regular pattern.
20) What kind of compound is formed when only non-metals are present in the compound?
A: covalent compound
Science 10 Chemistry Unit Review
21) Suppose that element “M” is a metal with two valence electrons. Element “X” is a non metal
with five valence electrons. When they combine chemically, they form and ionic compound.
What could be the chemical formula of this compound?
a) NF
b) MgO
c) Cu3N
d) Ca3P2
A: d: Ca3P2 ; metal first Ca+2 nonmetal second p-3
Crossover charges, drop, get rid of +/- : Ca3P2
22) Write the skeleton equation for each reaction and then balance
a) sodium + oxygen → sodium oxide: 4Na + O2 → 2Na2O
b) magnesium + copper (II)chloride → copper + magnesium chloride
Mg + CuCl2 → Cu + MgCl2
c) calcium carbonate → calcium oxide + carbon dioxide:
CaCO3 → CaO + CO2
d) chromium (III)chloride + potassium hydroxide →
potassium chloride + chromium(III)hydroxide: CrCl3 + 3K OH → 3KCl + Cr(OH) 3
e) sodium acetate + manganese(II)nitrate → manganese(II)acetate + sodium nitrate:
2NaCH3COO + Mn(NO3)2 → Mn(CH3COO) 2 + 2NaNO3
23) Name the following:
a) CO2 carbon dioxide
b) N2O dinitrogen monoxide
c) S2F10 disulphide decafluoride
d) NI3
nitrogen triiodide
e) PCL5 phosphorus pentachloride
24) Write the formula for the following:
N2S4
a) dinitrogen tetrasulfide:
SO3
b) sulfur trioxide:
c) phosphorous pentabromide: PBr5
Chapter 5
1) What is the pH scale?
A: a # scale for measuring how acidic or basic a solution is
2) What pH values are acids found between? What about bases?
A: Acids: 0-7 Bases: 7-14
3) What is the pH of water? What does this pH mean?
A: 7, neutral
4) What types of substances are labeled as acidic on the pH scale? Which ones are basic? (list all
examples from the scale)
Acidic → stomach acid, lemon, grapes, tomatoes, bananas, milk
Basic → oven cleaner, bleach, ammonia, soap, baking soda, eggs
Science 10 Chemistry Unit Review
5) What are the different types of pH indicators and at what pH does each change color (what
change in color is observed for each?)
Acid-base indicator
pH range of colour change Colour changes as pH rises
-methyl orange
3.2 - 4.4
Red → yellow
-methyl red
4.8 - 6.0
Red – yellow
-bromothymol blue
6.0 - 7.6
Yellow – blue
-litmus
7.0
Red – blue
-phenolpthalein
8.2 - 10.0
Colourless – pink
-indisocar mine
11.2 – 12.0
Blue - yellow
6) What color does blue litmus paper turn in an acid? In a base? In a neutral solution?
A: Red; blue; blue
7) What color does red litmus paper turn in an acid? In a base? In a neutral solution?
A: Red; blue; red
8)
What atom do acids usually start with?
9) What atoms do bases usually end with?
A: H, e.g. H2SO4
A: OH, eg. NaOH
10) What are the naming rules for acids?
A:
-Names that begin with “hydrogen” and end in ate
- drop the “hydrogen and change suffix to ic acid.
- Eg. H2CO3: Hydrogen carbonate → carbonic acid
-Names that begin with “hydrogen” and end in ite
- drop the “hydrogen” and change suffix to ous acid.
- Eg. H2SO4: Hydrogen sulphite → Sulfurous acid
- Acids that don’t contain polyatomics:
- add hydro to the beginning and end in ic acid.
- Eg. HCl → HCl (ag) = hydrogen chloride → hydrochloric acid
11) Finish the following equations: (remember in each you should get a salt and either a water, a
gas or both water and a gas, specify the gas by writing its chemical formula)
Acid + base → salt + water (H2O)
Acid + metal → salt + hydrogen gas (H2(g))
Acid + CaCO3 → salt + water (H2O) + carbon dioxide gas [CO2(g)]
12) How can you tell whether a compound is organic or inorganic by looking at its chemical
formula?
A:
Organic: contains both C + H
Inorganic: do not contain both in the formula, may have one but not the other.
13) Be able to recognize the different types of structures of organic compounds.
A: see table 5.8. p. 247
14) What is the difference between hydrocarbons and alcohols (hint: look at the difference in the
chemical formula)?
A: hydrocarbons – C + H alcohols – C, H, O
Science 10 Chemistry Unit Review
15) What value for pH would you expect for each of the following?
a. bananas: 5
b. ammonia (NH3) window cleaning solution: 11
c. milk: 6
16) What is the colour of bromothymol blue indicator in each of the following:
a. stomach acid: yellow
b. egg white: blue
c. water: green
17) a) If the pH of a solution drops from 5 to 4, has the acidity increased or decreased?
A: increased
b) By how many times has the pH increased or decreased?
A: 10 times
18) Classify each of the following compounds as organic or inorganic by examining its chemical
formula
a) CH3CH2CH2OH - organic
b) Na2C2O4
- inorganic
c) Na4C
- inorganic
d) CH3COOH
- organic
e) MgCO3
- inorganic
f) AlCl3
- inorganic
g) CH4
- organic
h) CO2
- inorganic
19) Which of the following compounds are hydrocarbons?
A: Only C + H = a) C4H10 c) C6H6
20) A piece of red litmus is placed into a solution and it remains red. Blue litmus paper is placed
into the same solution, and it remains blue. What is the pH of the solution?
A: b) 7
21) What is the pH of a solution that is yellow in methyl orange indicator and red in methyl red
indicator?
A: c) 4.5
22) A solution of unknown identity is tested using acid-base indicators. The solution causes
phenolphthalein to turn pink and causes indigo carmine to turn blue. Which of the following is
consistent with these results?
A: c: ammonia
23) A spill kit for the treatment of acid spills contains magnesium oxide and sodium carbonate.
Why are these chemicals useful for neutralizing acids?
A: a) both are bases
Chapter 6
1) Identify the reaction type of each of the following chemical reactions
a) S8 + 8O2 → 8SO2 =
synthesis
b) 2Au + N2 → 1AuN =
synthesis
c) 2HF → H2 + F2
=
decomposition
d) CH4 +2O2 → CO2 + 2H2O =
combustion
e) H2SO4 + 2NaOH → Na2SO4 + 2H2O
=
neutralization
f) HI + CsOH → CsI +H2O =
neutralization
g) Fe(NO3)3 + 3KCl → FeCl3 + 3KNO3
=
double replacement
Science 10 Chemistry Unit Review
2) Complete each reacton:
a) Ca + CuF2 → CaF2 + Cu
b) 4 Rb + O2 → 2 Rb2O
c) 2 C3H7OH + 9 O2 → 6 CO2 + 8 H2O
d) 2 Cl2 + PbI4 → PbCl4 + 2 I2
e) 2 Li2O → 4 Li + O2
f) 2 HF + Ca(OH)2 → CaF2 + 2 H2O
g) Ba + Ni(NO3)2 → Ba(NO3)2 + Ni
h) 2 Al + 3 I2 → 2 AlI3
i) 2 AgNO3 + Na2CrO4 → Ag2CrO4 + 2 NaNO3
25) Which of the four factors affection reaction rate is most important in each example below?
a) you place food in a refrigerator so it does not spoil: temperature
b) you use extra laundry soap to help remove stains from clothes: concentration
c) a person rescued from a burning house is given oxygen: concentration
d) a baby’s food produces an enzyme to help it digest milk more quickly: catalyst
e) you grind up a lump of sugar to help it dissolve faster: surface area
f) an acetylene blowtorch has extra oxygen added to the mix to help cut through steel:
concentration
26) You may have noticed on cold days that there is often liquid dripping from the tailpipes of cars.
Which of the following explains this observation?
A: d) the liquid is water, which is produced during combustion of gasoline
27) When copper is exposed to the weather, it slowly turns blue-green. When silver tarnishes, it
becomes black. What class of chemical reaction is illustrated by these observations?
A: a) synthesis
28) Nitrogen monoxide is a poisonous gas that is produced during the combustion of gasoline.
Nitrogen monoxide decomposes extremely slowly to produce nitrogen and oxygen. However,
in the presence of platinum metal, the reaction occurs instantly. What is the role of platinum in
speeding up this reaction?
A: d) platinum is a catalyst that decomposes the nitrogen monoxide
29) Many countries rely on the burning of coal for the production of electrical energy. Coal often
contains sulfur, which forms trioxide when it is burned. How does the burning of coal
contribute to precipitation that has a low pH?
A: b) sulfur oxides form acidic solutions
Chapter 7
1) List three types of radiation that are released as a result of radioactive decay.
A: alpha, beta, gamma
2) What are isotopes?
A: atoms of the same element that differ in the # of neutrons
3) Write the nuclear symbols that represent each of the following.
a) proton (one symbol):
b) neutron (one symbol):
c) beta decay (two symbols)
d) gamma decay (one symbol):
e) alpha decay (two symbols)
Science 10 Chemistry Unit Review
4) How are atoms in Oxygen-16 and Oxygen-17 similar?
A: both have 8 protons and 8 electrons
5) How does the release of a beta particle from the nucleus of an atom turn the atom into a
different element?
A: a neutron decays into other particles including a proton and an electron. The electron
escapes the nucleus as a beta particle. The proton remains in the nucleus increasing the
atomic # by one; this creates a new element.
6) Complete the following table:
Isotope
Mass #
Helium-3
3
Helium-4
4
Nitrogen-14
14
Nitrogen-15
15
18
Oxygen-18
20
Neon-20
Atomic #
2
2
7
7
8
10
# of neutrons
1
2
7
8
10
10
7) How does a fusion nuclear reaction differ from a fission nuclear reaction?
A:
Nuclear fusion: small atomic nuclei combine to form larger nuclei; release of
energy
Nuclear fission: larger atomic nuclei are split into smaller nuclei; release of energy
8) What are two main uses of fission nuclear reactions?
A: generate electricity; nuclear weapons; medical isotopes
9) A sample of rock contains 40g of radioisotope. How much of the radioisotope will remain after
three half lives?
A: 1 half-life = 20g; 2 half-lives = 10g; 3 half-lives = 5g
10) Refer to table 7.6 on p.307, for information of the radioactive decay of Uranium-235.
a) What is the approximate age of rock that can be dated by U-235:
A: 10 million years
b) What is the ratio of U235 to Pb-207 present is a sample after one half life?
A: 1:1
c) How many years does it take for 32g of U-235 to decay into 8g of U-235?
A: 1420 million years (2 half lives)
11) Provide the nuclear symbol for the parent nucleus of each of the following:
Science 10 Chemistry Unit Review
12) Complete each nuclear equation given the type of decay process involved.
a)
b)
c)
13) Classify each nuclear equation as alpha, beta or gamma decay.
14) Complete the following nuclear equations.