G 10
Chemistry worksheet
Chapter 6
Chemical Reactions and Equations
Name:……Answer
Key……… Section:……Date:………………….
Part One: Multiple Choices
1. All the following are clues that a chemical reaction has taken place except
A.
B.
C.
D.
a flame occurs
a color change
a solid forms
the reactant is smaller
2. You are asked to balance the chemical equation H2 + O2  H2O. How
many of the following ways are correct ways to balance this equation?
I.
2H2 + O2  2H2O correct
II. H2 + 1/2O2  H2O correct
III. 4H2 + 2O2  4H2O correct
IV. H2 + O2  H2O2 wrong
A.
B.
C.
D.
1
3
2
4
3. When the following equations are balanced using the smallest possible
integers, what is the coefficient in front of the underlined substance in each
case?
Br2 (l)  KI(aq)  I 2 (aq)  KBr (aq)
2
B. 6
C. 3
D. 4
4. When the following equations are balanced using the smallest possible
integers, what is the coefficient in front of the underlined substance in each
case? N 2 ( g) O2 ( g)  N 2O3
A.
A.
B.
C.
D.
6
3
2
4
5. When the following equations are balanced using the smallest possible
integers, what is the coefficient in front of the underlined substance in each
case? AI 2O3 ( s)  H 2SO4 (aq)  AI 2 (SO4 ) 3 (aq) H 2O(l)
A.
B.
C.
D.
3
2
9
6
6. A(n) _____ reaction is one in which two or more substances combine to form
a single product.
A. Synthesis
B. Decomposition
C. Single replacement
D. Double replacement
7. An example of a(n) _____ reaction is the electrolysis of water, in which an
electric current breaks down water into two new substances.
A. Synthesis
B. Single replacement
C. Double replacement
D. Decomposition
8. This chemical reaction Zn + CuCl2 → ZnCl2 + Cu is an example of:
A. Synthesis reaction
B. Double Displacement reaction
C. Single Displacement
D. Decomposition
9. Heating sodium bicarbonate in baking bread gives out carbon dioxide which
causes the bread to rise. The following reaction 2NaHCO3 → Na2CO3 + H2O
+ CO2 is:
A. Synthesis reaction
B. Double Displacement reaction
C. Single Displacement
D. Decomposition
10.
Fe + O2 →Fe2O3 is an example of :
A. Synthesis reaction
B. Double replacement reaction
C. Single replacement reaction
D. Decomposition reaction
11.
This chemical reaction KOH + H2SO4 → K2SO4 + H2O is an example
of:
A. Synthesis reaction
B. Decomposition reaction
C. Single Displacement reaction
D. Double Displacement reaction
Part Two: Short answers
1. Aluminum oxide solid reacts with gaseous carbon monoxide to
produce aluminum metal and carbon dioxide gas. Write the
balanced equation for this reaction.
2. Write the word balanced equation for this reaction of the
following reaction
Na(s) + H2O (l) → NaOH (aq) + H2(g)
Metal sodium + Liquid water → aqueous sodium hydroxide + Hydrogen gas
3. Use the following choices to classify the following reactions.
a.
b.
c.
d.
e.
Combustion
Synthesis
Single Displacement
Double Displacement
Decomposition
1. 2HgO (s) → 2 Hg (l) + O2 (g) Decomposition
2. C3H8 (g) + 5O2 (g) → 3CO2(g) + 4H2O(g) Combustion
3. 2H2O(l) → 2H2(g) + O2 (g) Decomposition
4. Na2SO4 (aq) + Pb( NO3)2 (aq) → PbSO4 (s) + 2 NaNO3 (aq)
Double Displacement
5. H2SO4 (aq)+ Ba(OH)2(aq)→ 2H2O(l) + BaSO4 (s)
Double Displacement
6. S8 (s) + 12O2 (g) → 8SO2 (g)
Combustion
7. Zn(s) + HCl(aq) → H2(g) + ZnCl2(aq) Single Displacement
8. KBr(aq) + AgNO3 → AgBr (s) + KNO3 (aq)
Double Displacement
9. 6Na (s) + N2 (g) →2 Na3N (s) Synthesis
10.
NH4HS(s) → NH3(g) + H2S(g) Decomposition
4. Why is it important to balance a chemical equation?
_____Because it is important to distinguish between the 5 major types of
chemical reactions and to classify them.
5. Classify the following chemical equations as endothermic and
exothermic reaction:
a. 3H2 + N2 →2NH3 + Energy
Energy is released
Exothermic reaction
b. CaCO3 + Energy → CaO + CO2
Energy is absorbed
Endothermic reaction
c. 2SO2+O2 →2SO3 + Energy
Energy is released
Exothermic reaction
d. 2KClO3 + Heat →2KCl + 3O2
Energy is absorbed
Endothermic reaction
Combustion reaction of any hydrocarbon will produce carbon dioxide
and water and energy. This is an example:
Word equation: Propane + oxygen gas→ water + carbon Dioxide +energy
Chemical equation: C3H8+ O2→H2O +CO2dioxide+energy