Unit 9 Test – Chemistry I
DIRECTIONS: Solve the following problems. Show all of your work and circle your final
answer.
1.) What mass (in grams) of hydrogen gas is
produced if 20.0 moles of zinc are added to
excess hydrochloric acid according
to the following equation?
Zn (s) + 2 HCl (aq) à ZnCl2
(aq) + H2
(g)
20.0
moles ? g
1.) Already done! J
2.) 20.0 moles Zn = x moles H2 1 . x = 20.0 . 1
1
1 x = 20.0 moles
H2
3.) 20.0 moles H2 .
2 g/mole = 40.0 grams H2
2.) What mass (in grams) of 1 – chloropropane (C3H7Cl) is produced if
400. grams of propane
(C3H8) react
with excess chlorine gas according to the following equation?
C3H8 +
Cl2 à C3H7Cl + HCl
400. g ? g
1.) 400.
g C3H8 = 9.09 moles C3H8
44 g/mole
2.) 9.09
moles C3H8 = x moles C3H7Cl 1. x = 9.09 . 1
1 1 x = 9.09 moles C3H7Cl
3.) 9.09
moles C3H7Cl . 78.5
g/mole = 714 g C3H7Cl
3.) What mass (in grams) of sodium hydroxide is produced
if 20.0 grams of sodium metal
reacts with excess water according
to the following chemical equation?
2 Na (s) + 2 H2O (l) à 2 NaOH (aq) + H2 (g)
20.0 g ? g
1.) 20.0
g Na = 0.870 moles Na
23 g/mole
2.) 0.870
moles Na = x moles NaOH 2
. x = 0.870 . 2
2 2 2x
= 1.74
x
= 0.870 moles NaOH
3.) 0.870
moles NaOH
. 40 g/mole = 34.8
g NaOH
SELECT THE BEST ANSWER AND
WRITE IT TO THE LEFT OF THE NUMBER OF THE QUESTION.
4.) For the reaction, 2 H2 + O2 à 2 H2O
, how many grams of water are produced from
6.00 moles of hydrogen?
(A) 2.00 g (B)
6.00 g (C) 54.0 g (D) 108 g
1.) already done for you!
2.)
6.00 moles H2 = x moles H2O 2 .
x = 6.00 . 2
2 2 2x
= 12
x
= 6.00 moles H2O
3.)
6.00 moles H2O . 18
g/mole = 108 g
5.) For the reaction, 3 Fe
+ 4 H2O à Fe3O4 + 4 H2
, how many moles of iron oxide are
produced from 5.0 x 102
grams of iron?
(A) 1.0 mole (B) 3.0 moles (C) 9.0 moles (D) 12 moles
1.) 5.0 x 102 g Fe = 8.93 moles Fe
56 g/mole
2.)
8.93 moles Fe = x moles Fe3O4 3 .
x = 8.93 . 1
3 1 3x = 8.93
x
=2.98 moles Fe3O4
3.) not needed! J
6.) For the reaction, CH4 + 2 O2 à CO2 + 2 H2O
, how many moles of carbon dioxide are
produced from the combustion of
100. grams of methane (CH4)?
(A) 6.23 moles (B)
10.8 moles (C) 12.5 moles (D) 25 moles
1.) 100. g CH4
= 6.25 moles CH4
16 g/mole
2.)
6.25 moles CH4 = x moles CO2 1 .
x = 6.25 . 1
1 1 x = 6.25 moles CO2
3.) not needed! J
7.) For the reaction, Cl2 + 2 KBr à 2 KCl + Br2 , how many moles of potassium
chloride
are produced from 119 grams of
potassium bromide?
(A) 0.119 moles (B)
0.236 moles (C) 0.581 moles (D) 1.00 mole
1.)
119 g KBr = 1.00 mole KBr
119 g/mole
2.)
1.00 mole KBr = x moles KCl 2 .
x = 1.00 . 2
2 2 2x = 2.00
x
= 1.00 mole KCl
3.)
not needed
8.) For the reaction, 2 H2 + O2 à 2 H2O
, how many moles of water can be produced from
6.0 moles of oxygen?
(A) 2.0 moles (B)
6.0 moles (C) 12 moles (D) 18 moles
9.) In the reaction, N2 + 3 H2 à 2 NH3
, what is the mole ratio of nitrogen (N2) to
ammonia (NH3)?
(A) 1 : 1 (B) 1 : 2 (C)
1 : 3 (D) 2 : 3
10.) In the reaction, 2 Al2O3 à 4 Al + 3 O2
, what is the mole ratio of aluminum to
oxygen?
(A) 10 : 6 (B) 3 : 4 (C)
2 : 3 (D) 4 : 3
11.) In the reaction, 2 H2 + O2 à 2 H2O
, what is the mole ratio of oxygen to water?
(A) 1 : 2 (B) 2 : 1 (C)
8 : 1 (D) 1 : 4
12.) In the reaction, Ca
+ Cl2 à CaCl2
, what is the mole ratio of chlorine to calcium
chloride?
(A) 2 : 3 (B) 2 : 1 (C)
1 : 2 (D) 1 : 1
13.) In the chemical reaction, w A + x B à y C + z D
, a comparison of the number of
moles of A to the number of moles
of C would be a(n)
(A) mass ratio (B) mole ratio (C)
electron ratio (D) energy proportion
14.) The Haber process for producing ammonia
commercially is represented by the equation,
N2 (g) + 3 H2 (g) à 2 NH3
(g). To completely convert 9.0 moles of
hydrogen gas to
ammonia gas, how many moles of
nitrogen gas are required?
(A) 1.0 moles (B) 2.0 moles (C) 3.0 moles (D) 6.0 moles
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