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Worksheets

STOICHIOMETRY & MORE

Total questions: 46

Worksheet time: 5hrs 58mins

Name
Class
Date
1.
CH4  +  2O2  →  CO2  +  2H2O
24 grams of CH4 was added to the above reaction. Calculate the theoretical yield of CO2.
a)
66 grams
b)
132 grams
c)
33 grams
d)
8.72
2.
The ______________ yield is the maximum amount of product possible in a reaction. This determines the amount of product that should be produced in a perfect setting
a)
Percent
b)
actual
c)
stoichiometry
d)
theoretical
3.

2Fe2O3 + 3C → 4Fe + 3CO2

You add 28 grams of carbon. You find the actual yield to be 81.2 grams of CO2. What is the percent yield of CO2? (Hint: calculate theoretical yield of CO2 first)

a)

58.83%

b)

308%

c)

6435%

d)

79.14%

4.
Theoretical yield = 73g
Actual yield = 62g
Calculate the percent yield.
a)
1.16%
b)
116%
c)
85%
d)
76%
5.
P+ 6Cl--> 4PCl
The reaction of 75.0g P4 with excess chlorine gas produces 110g PClin lab. Find the theoretical yield and calculate percent yield for the reaction. 
a)
78%
b)
64%
c)
27%
d)
33%
6.
Lead nitrate can be decomposed by heating.  What is the % yield of the decomposition reaction if 7.4g Pb(NO3)2 are heated to give 4.1 g PbO?
2Pb(NO3)2 (s)→2PbO(s)+4NO2(g)+O2(g)
a)
82%
b)
44%
c)
56%
d)
67%
7.

What is the formula for percent yield?

a)

actual yieldtheoretical yield×100\frac{actual\ yield}{theoretical\ yield}\times100

b)

theoretical yieldactual yield×100\frac{theoretical\ yield}{actual\ yield}\times100

c)

moles Amoles B\frac{moles\ A}{moles\ B}

d)

grams Agrams B\frac{grams\ A}{grams\ B}

8.

If you are converting from grams of substance A to grams of substance B, drag the correct order of the conversion process:

​ (a)   ---> ​ (b)   ---> ​ (c)   ---> ​ (d)  

Choose from the below words
Grams A
Moles A
Moles B
Grams B
9.

Based on the following equation and question, choose the actual yield:

Zn  +  2HCl      ZnCl2  +  H2Zn\ \ +\ \ 2HCl\ \ \ \rightarrow\ \ \ ZnCl_2\ \ +\ \ H_2

20 g of (136.286 g/mol) is formed in a lab. What is percent yield if 10 g of HCl (36.453 g/mol) is consumed?

a)

44.5%

b)

35.4%

c)

10.6 %

d)

26.8 %

10.

Calculate percent yield based on the following information:

Actual Yield: 50

Theoretical Yield: 60

a)

0.8333 %

b)

83.33 %

c)

120 %

d)

1.2 %

11.
Which of the following do you get through measuring its mass? (No calculations)
a)
percent yield
b)
theoretical yield
c)
actual yield
d)
limiting reagent
12.

Which of the following reactions has the lowest percent yield?

a)

Theoretical yield 25.7 g; actual yield 23.2 g

b)

Theoretical yield 42.1 g; actual yield 39.9 g

c)

Theoretical yield 18.2 g; actual yield 15.6 g

d)

Theoretical yield 93.4 g; actual yield 87.9 g

13.
Using the following equation:
Fe2O3(s) + 3H2(g) → 2Fe(s) + 3H2O(l)
How many moles of iron can be made from  6 moles H2
a)
4 moles Fe
b)
6 moles Fe
c)
9 moles Fe
d)
2 moles Fe
14.
N2 +  3H2 → 2NH3 
How many moles of hydrogen are needed to react with 2 moles of nitrogen?
a)

6 mol H

b)

2 mol H

c)

3 mol H

d)

1 mol H

15.
2H2   +   O2  →  2H2O
How many moles of water can be produced if 8 moles H2 are used?
a)
4 moles
b)
8 moles
c)
16 moles
d)
2 moles
16.
2 NaClO3 (s) --> 2NaCl (s) +3 O2 (g)  
12.00 moles of NaClO3 will produce how many grams of O2?
a)
256 g of O2
b)
576 g of O2
c)
288 g O2
17.
B2H6 + 3O2 -->2 HBO2 + 2 H2O
 What mass of O2 will be needed to burn 36.1 g of B2H6?
a)
13.8 g O2
b)
3.86 mol of O2
c)
124 g O2
18.
4 Al + 3 O2 –> 2 Al2O How much aluminum would be needed to completely react with 45 grams of O2?
a)
1.05 moles
b)
3.75 moles
c)
1.875 grams
d)
1.875 moles
19.
2Al + 3H2SO4 -> Al2(SO4)3 + 3H2
How many grams of aluminum sulfate would be formed if 250g H2SO4 completely reacted with aluminum?
a)
0.85 g
b)
290 g
c)
450 g
d)
870 g
20.
Mg(s) + 2 HCl(aq)  -->  MgCl₂(aq)   + H₂(g)
How many moles of HCl are consumed in the production of 7.5 moles of MgCl₂?
a)
3.8 moles
b)
15 moles
c)
7.5 moles
d)
23 moles
21.
Balance the following reaction :
 
CaC₂(s)   +   H₂O(l)   -->   C₂H₂(g)   +   Ca(OH)₂(aq)
a)
1,2,2,2
b)
1,2,1,1
c)
2,1,1,1
d)
2,1,2,1
22.
 CaC₂(s) + 2H₂O(l)   -->   C₂H₂(g)   + Ca(OH)₂(aq)
how many grams of Ca(OH)₂ would be formed with 3.20 moles of CaC₂?
a)
119 g
b)
21.2 g
c)
114 g
d)
237 g
23.
Use the following equation:
NaIO3(aq) + 6HI(aq) --> 3I2(s) + NaI(aq) + 3H2O(l)
How many moles of iodine can be made from 6.55 moles of NaIO3?
a)
4.55 moles I2
b)
23.18 moles I2
c)
19.65 moles I2
d)
34.99 moles I2
24.
Using the following equation:
4NH3(g) + 5O2(g) --> 4NO(g) + 6H2O(l)
How many grams of oxygen gas are needed to react with 56.8 grams of ammonia?
a)
45.08 g O2
b)
133.33 g O2
c)
260.77 g O2
d)
75.92 g O2
25.
If a chemist calculates the maximum amount of product that could be obtained in a chemical reaction, he or she is calculating the
a)
theoretical yield
b)
mole ratio
c)
actual yield
d)
percentage yield
26.
2 KClO3 → 2 KCl + 3 O2
How many moles of oxygen are produced when 6.7 moles of KClO3 decompose completely?
a)
6.7 mol
b)
1.0 mol
c)
10.1 mol
d)
4.5 mol
27.
2Na + 2H2O → 2NaOH+ H2
How many grams of hydrogen are produced if 120 g of Na are available?
a)
5.2 g
b)
2.6 g
c)
690 g
d)
45 g
28.
 SiO2 + 3C → SiC + 2CO
I need to add 8 moles of Carbon to the reaction. How many grams of Carbon should I weigh?
a)
96 g
b)
0.67 g
c)
2.67 g
d)
48 g
29.
Cl2 + 2 KBr → Br2 + 2 KCl
How many grams of potassium chloride can be produced from 356 g of chlorine and 356 g of potassium bromide?
a)
749 g
b)
223 g
c)
479 g
d)
814 g
30.
CH4 + 2 O2 → CO2 + 2 H2O
How many moles of carbon dioxide are produced from the combustion of 110 g of CH4?
a)
13.7 mol
b)
2.75 mol
c)
6.11 mol
d)
6.85 mol
31.
Fe (s) + S (l) --> FeS (s)  

In the experiment above, 7.62 g of Fe are allowed to react with 8.67 g of S.
How much FeS is formed?
a)
14.8 g
b)
12.2 g
c)
13.7 g
d)
19.9 g
32.
Identify the limiting reagent when 6.00 g HCl combines with 5.00 g Mg to form MgCl2.
 
Mg +  2HCl --> MgCl2  +  H2   
 
a)
Mg
b)
H2
c)
MgCl2
d)
HCl
33.
When does a chemical reaction stop?
a)
When the lab is finished
b)
When the excess reactant is used up
c)
When the limiting reactant is used up
d)
Chemical reactions never stop
34.
CH4  +  2O2  →  CO2  +  2H2O
24 grams of CH4 was added to the above reaction. Calculate the theoretical yield of CO2.
a)
66 grams
b)
132 grams
c)
33 grams
d)
8.72
35.

When reacting Na with Cl2, we calculated that the theoretical yield should be 13 grams. Our actual yield was 12.5 grams. What is the percent yield?

a)

90.4%

b)

104%

c)

96.15%

d)

1.04%

36.

2Fe2O3 + 3C → 4Fe + 3CO2

You add 28 grams of carbon. You find the actual yield to be 81.2 grams of CO2. What is the percent yield of CO2? (Hint: calculate theoretical yield of CO2 first)

a)

58.83%

b)

308%

c)

6435%

d)

79.14%

37.
P+ 6Cl--> 4PCl
The reaction of 75.0g P4 with excess chlorine gas produces 110g PClin lab. Find the theoretical yield and calculate percent yield for the reaction. 
a)
78%
b)
64%
c)
27%
d)
33%
38.

11.

LiOH + KCl → LiCl + KOH


b) I actually produced 6 grams of lithium chloride and I began this reaction with 20.0 grams of lithium hydroxide. What is my percent yield?

a)

16.9%

b)

5.91%

c)

1.88%

d)

12.3%

39.
In a lab, a scientist calculate he should produce 12.3 grams of product in his experiment. When he is finished collecting his product it weighs 10.1 grams. What is his percent yield?
a)
82%
b)
0.82%
c)
10.1 %
d)
100%
40.

The reaction of 25.0 g benzene, C6H6, with excess HNO3 resulted in 21.4 g C6H5NO2. What is the percentage yield?

C6H6 + HNO3 → C6H5NO2 + H2O

a)

100%

b)

27.39%

c)

54.29%

d)

85.62%

41.
Lead nitrate can be decomposed by heating.  What is the % yield of the decomposition reaction if 7.4g Pb(NO3)2 are heated to give 4.1 g PbO?
2Pb(NO3)2 (s)→2PbO(s)+4NO2(g)+O2(g)
a)
82%
b)
44%
c)
56%
d)
67%
42.

What is the limiting reactant if 16 moles of NH3 and 30.0 moles of NO are combined?

4NH3 + 6NO --> 5N2 + 6H2O

a)

NH3

b)

NO

c)

N2

d)

water

43.

CH4 + 2H2O --> CO2 + 4H2

What is the limiting reactant when 20g CH4 and 15g H2O are combined? (CH4 = 16.05 g/mol; H2O = 18.02 g/mol)

a)

CH4

b)

H2O

c)

CO2

d)

H2

44.

P4 + 3O2 --> P4O6

What is the limiting reactant when 5 moles of P4 and 15 moles of O2 are combined?

a)

P4

b)

O2

c)

P4O6

d)

none of the above

45.

Fe + S --> FeS

If 7.62g Fe and 8.67g S are combined, what is the limiting reactant? (Fe = 55.85 g/mol; S = 32.07 g/mol)

a)

Fe

b)

S

c)

FeS

d)

none

46.

3CaCO3 + 2FePO4 --> Ca3(PO4)2 + Fe2(CO3)3


Assuming we start with 100. g of CaCO3 and 45 g of FePO4, identify the limiting reactant. (CaCO3 = 100.09 g/mol; FePO4 = 150.82 g/mol)

a)

iron(V) phosphate

b)

calcium carbonate

c)

iron(III) phosphate

d)

calcium(II) carbonate