NAME:
Awwuk'rf
Practice Test: Introduction to Chemical Reactions
PART A: Multiple Choice Write the letter of the choice that best completes the statement or answers the question
in the blank provided.
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1. A substance that enters into a chemical reaction is called a
a. mole.
c. coefficient.
b. product.
d. reactant.
2. In a reaction in which hydrogen reacts with oxygen to produce water, which substances are the reactants?
a. hydrogen only
c. both hydrogen and oxygen
b. oxygen only
d. water
3. Which of the following is not an example of a chemical change?
a. rusting iron
c. cutting paper
b. an apple ripening
d. a piece of wood burning
4. In a chemical equation, the symbol that takes the place of the words reacts with is a(n)
a. equal sign.
c. plus sign.
b. coefficient.
d. arrow.
D
5. In a chemical equation, the symbol that takes the place of the word yields is a(n)
a.
b.
A
;D
equal sign.
coefficient.
c.
d.
plus sign.
arrow.
6. When oxygen is available, sulfur dioxide is produced from the burning of sulfur. Which of the following word
equations best represents this reaction?
a. sulfur + oxygen ~ sulfur dioxide
b. sulfur dioxide + oxygen ~ sulfur
c. sulfur dioxide ~ sulfur + oxygen
d. sulfur ~ sulfur dioxide + oxygen
7. The word equation "magnesium reacts with chlorine-ts produce magnesium chloride" would be
represented by which of the following formula equations?
a. Mg ~ Cl2 + MgC12
b. MgCh ~ Mg+ Ch
.D
c.
d.
MgCl2 + Mg ~ Cl2
Mg + Cl2 ~ MgCl2
8. Which of the following is true of a balanced equation?
a. The number of atoms per molecule remains the same.
b. The kinds of atoms remain the same.
c. The total number of molecules remains the same.
d. The number of atoms of each element remains the same
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9. In a chemical reaction, what is the relationship between the total mass of the reactants and the total
mass of the products?
a. They must be equal.
b. The mass of the products must be greater.
c. The mass of the reactants must be greater.
d. There is no general relationship between the two.
10. In a chemical equation, the number of molecules of a given substance is indicated by a
~
a.
b.
D
subscript.
coefficient.
c.
d.
superscript.
reaction number.
11. How many atoms of oxygen are represented in 2 Ca(N03)2?
a.
4
c.
10
b. 6
d.
12
12. In balancing a chemical equation, which of the following are you allowed to do?
a. change subscripts
c. change superscripts
b. write coefficients
d. add new substances
C.t
A
13. The symbol (s) written after a formula in a chemical equation stands for
a. soluble.
c. solid.
b. solution.
d. synthesis.
14. Which of the following symbols means a substance is in water solution?
a.
b.
(aq)
(s)
c.
d.
(w)
(l)
15. What is the general form for a single-replacement reaction?
a. AX + BY ~ A Y + BX
c. A + B ~ AB
b. AB ~ A + B
d. A + BX ~ AX + B
A
16. What is the general form for a double-replacement reaction?
AX + BY ~ A Y + BX
b. AB~A+B
a.
A + B ~ AB
d. A+BX~AX+B
c.
17. What kind of reaction is represented by the equation C2Cl4 + C12 ~ C2C16?
a. synthesis
c. single replacement
b. double replacement
d. combustion
1·8.A chemical reaction has NOT occurred if the products have
a. the same mass as the reactants.
b. less total bond energy than the reactants.
c. more total bond energy than the reactants.
d. the same chemical properties as the reactants.
19. Which observation does NOT indicate that a chemical reaction has occurred?
a. formation of a precipitate
c. evolution of heat and light
b. production of a gas
d. change in total mass of substances
2
A-
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20. A solid produced by a chemical reaction in solution that separates from the solution is called
a. a precipitate.
c. a molecule.
b. a reactant.
d. the mass of the product.
21. After the correct formula for a reactant in an equation has been written, the
a. subscripts are adjusted to balance the equation.
b. formula should not be changed.
c. same formula must appear as the product.
d. symbols in the formula must not appear on the product side of the equation.
22. In writing an equation that produces hydrogen gas, the correct representation of hydrogen gas is
a. H.
c. H2.
b. 2H.
d. OH.
23. To balance a chemical equation, it may be necessary to adjust the
a. coefficients.
c. formulas of the products.
b. subscripts.
d. number of products.
24. According to the law of conservation of mass, the total mass of the reacting substances is
a. always more than the total mass of the products.
b. always less than the total mass of the products.
c. sometimes more and sometimes less than the total mass of the products.
d. always equal to the total mass of the products.
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25. For the formula equation 2Mg + 02 ~ 2MgO, the word equation would begin
a. Manganese plus oxygen. . .
c. Magnesium plus oxygen ...
b. Molybdenum plus oxygen. . .
d. Heat plus oxygen ...
26. After the first steps in writing an equation, the equation is balanced by
a. adjusting subscripts to the formula(s).
b. adjusting coefficients to the smallest whole-number ratio.
c. changing the products formed.
d. making the number of reactants equal to the number of products.
A
c
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27. The reaction 2Mg(s) + 02(g) ~ 2MgO(s) is a
a. synthesis reaction.
c.
b. decomposition reaction.
d.
single-replacement reaction.
double-replacement reaction.
28. The reaction Mg(s) + 2HCl(aq)
a. composition reaction.
b. decomposition reaction.
is a
single-replacement reaction.
double-replacement reaction.
~ H2(g)
29. The reaction 2HgO(s) ~ 2Hg(l)
a. single-replacement reaction.
b. synthesis reaction.
+ MgCIz(aq)
c.
d.
+ 02(g) is a(n)
c.
d.
ionic reaction.
decomposition reaction.
30. The reaction Pb(N03)2(aq) + 2KI(aq) ~ Pblxs) + 2KN03(aq) is a
a.
b.
double-replacement
synthesis reaction.
reaction.
c.
d.
decomposition reaction.
combustion reaction.
31. The reaction 2KCl03(s) ~ 2KCl(s) + 302(g) is a(n)
a. synthesis reaction.
c. combustion reaction.
b. decomposition reaction.
d. ionic reaction.
3
~
32. In one type of synthesis reaction, an element combines with oxygen to yield a(n)
a. acid.
c. oxide.
b. hydroxide.
d. metal.
33. When a binary compound decomposes,
a. an oxide
b. an acid
34. In the equation 2AI(s) + 3Fe(N03)2(aq)
a. . nitrate.
b. water.
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what is produced?
c. a tertiary compound
d. two elements
~
3Fe(s) + 2Al(N03)3(aq),
c. aluminum.
d. nitrogen.
iron has been replaced by
35. In a double-replacement reaction, hydrogen chloride and sodium hydroxide react to produce sodium chloride.
Another product is
c. water.
a. sodium hydride.
b. potassium chloride.
d. hydrogen gas.
4
PRACTICE TEST (PART B): WORD EQUATIONS, BALANCING
EQUATIONS & IONIC EQUATIONS
Write a balanced chemical equation for each of the following word equations:
1. Aqueous beryllium chloride reacts with aqueous silver nitrate to produce
aqueous beryllium nitrate and solid silver chloride.
2. Isopropanol (C3HsO) burns in oxygen to produce carbon dioxide gas and water
vapor.
3. Solid sodium reacts with aqueous iron (II) chloride to produce solid iron and
aqueous sodium chloride.
Balance the equations below:
1)
2)
N2 + ~H2
~KCI03~
~ ~
~KCI+
3)
d-
4)
~H2+
5)
__
Pb(OH)2 + ~
6)
~
AIBr3 + ~
NaCI +
8)
C3H8 + ~
NaF +
HCI a>~
K2S04 ~
CI2
C02 + ~
02 a>~
d.S
~
C8H18 +
10)
__
FeCI3 +
11)
~P+~02a>~P205
12)
~
13)
~A920
..:!.-
Na + ~
02 ~
S8+ ~02
PbCI2
AI2(S04)3
H20
C02 + ~
H20
-.!!. C02 + l.!.-
NaOH ~ __
H20 a>~
a>~Ag
H20 + __
.Ia: KBr + __
02 a>
9)
H20
Fe(OH)3 + ~NaCI
NaOH + __
H2
+_02
~ ~S03
.s: H20 a>
15)
_~_
C02 +
16)
~K+
__
17)
~
18)
__
HN03 + __
19)
~
H20 +
21)
/J
02 a>~H20
CH4 + ~
20)
~02
F2 ~
7)
14)
NH3
C6H1206 + ~02
MgBra> ~KBr+
HCI +
0( NaBr +
H2S04 + ~
__
CaC03 a>
CaCI2 +
NaHC03 ~ __
02 ~ ~
Mg
H20 +
NaN03 + __
H20 + __
H202
CaF2 a>~
NaN02 a>~
NaF +
HN02 +
CaBr2
Na2S04
C02
C02
Write the complete ionic equation for each of the following balanced equations:
(a) Mg(N03)2 (aq) + Na2C03 (aq) ~ MgC03 (s) + 2 NaN03 (aq)
~
9)
a
+ .;J
tJO~ - WfJlT
.;z Nik T ~l
t:
CD3d-~)_~
(b) MnCh (aq) + (NH4)2C03 (aq) ~ MnC03 (s) + 2 NH4Cl (aq)
fY\",
a;h
CrW]).
01
ollJI-I/
~)
+
CJJ/~)
---7
n; CD.(,)
t-
,;)
AJI-/q
;"l + ,}(!j~)
Write the net ionic equation for each of the following complete ionic equations:
(a) Ni3+ (aq) + 3 N03 - (aq) + 3 K+ (aq) + P04 3-(aq) ~ NiP04 (s) + 3 K+ (aq) + 3 N03 - (aq)
(b) 2 Co3+(aq) + 6 Br " (aq) + 6 K+ (aq) + 3 S2-(aq) ~ C02S3 (s) + 6 K+ (aq) + 6 Br -(aq)
(c) 3 K+ (aq) + P04 3-(aq) + A13+(aq) + 3 N03 - (aq) ~ AIP04 (s) + 3 K+ (aq) + 3 N03 - (aq)