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Introduction to Stoichiometry

Total questions: 31

Worksheet time: 2hrs 33mins

Name
Class
Date
1.

Mole ratios are obtained from the

a)

balanced chemical equation

b)

periodic table

c)

molar mass

2.

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

3.

In the chemical reaction described by the equation

4Fe(s) + 3O2(g) --> 2Fe2O3(s),

the mole ratio of iron(III) oxide to iron is

a)

1:1

b)

1:2

c)

2:3

d)

4:1

4.
Mole ratios are obtained from the
a)
balanced chemical equation
b)
periodic table
c)
molar mass
5.
What is the mole ratio of H2O to H3PO4 in the following chemical equation?   P4O10 + 6 H2O --> 4 H3PO
a)
6:4
b)
4:6
c)
1:3
d)
3:1
6.
Molar mass is in units of ________.
a)
grams
b)
grams/mole
c)
mole
d)
moles/gram
7.

What can be determined from a balanced chemical equation?

a)

Mole ratio of any two substances in the reaction

b)

Energy released in the reaction.

c)

Electron configuration of all elements in the reaction.

d)

Mechanism involved in the reaction.

8.

What is stoichiometry?

a)

The quantitative study of amounts of reactants used and products formed in a chemical reaction.

b)

The study of the speed of reactions by looking at the products formed.

c)

The quantitative study of amounts of products used and reactants formed in a chemical reaction.

d)

The study of types of reactions

9.

The __________ in a balanced equation reveals the mole ratios of the substances involved.

a)

subscript

b)

coefficients

c)

superscript

d)

total number in each compound

10.

Using the following equation:

Fe2O3(s) + 3H2(g) → 2Fe(s) + 3H2O(l)

How many moles of water can be made from 6 moles H2?

a)

4 moles Fe

b)

6 moles Fe

c)

9 moles Fe

d)

2 moles Fe

11.

In the equation 2 Al2O3 --> 4 Al + 3 O2, what is the mole ratio of aluminum to oxygen (aluminum is asked for, oxygen is given)?

a)

10/6

b)

3/4

c)

4/3

d)

2/3

12.

In the reaction 2 H2 + O2 → 2 H2O what is the mole ratio of oxygen to water

a)

1/2

b)

2/1

c)

3/4

d)

4/3

13.
N2 +  3H2 → 2NH3 
How many moles of hydrogen are needed to react with 2 moles of nitrogen?
a)
6
b)
2
c)
3
d)
1
14.
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
15.

What is a mole ratio?

a)

An animal that burrows underground.

b)

How many moles of reactant are used up in a chemical reaction.

c)

The ratio of a reactant / product to a different one - compared by the number of particles.

d)

The process by which we multiply fractions by using numbers from a chemistry problem.

16.

Where are the numbers for a mole ratio found?

a)

They are part of the chemical formulas for the reactants / products.

b)

They are given in the problem.

c)

They are found on the periodic table for those elements.

d)

They are found as coefficients in the reaction's balanced chemical equation.

17.

2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

Ethane (C2H6) combusts in the above reaction. What is the mole ratio of ethane to oxygen gas?

a)
b)
c)
d)
18.

2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

Ethane (C2H6) combusts in the above reaction. What is the mole ratio of carbon dioxide to water?

a)
b)
c)
d)
19.

2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

A problem asks how many moles of oxygen gas are needed to react completely with 6 moles of ethane (C2H6). What is the first step in setting up the problem?

a)
b)
c)
d)
20.

2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

New problem: If 16 moles of carbon dioxide are formed by this reaction, how many moles of water were also produced?

a)

4 mol H2O

b)

6 mol H2O

c)

24 mol H2O

d)

96 mol H2O

e)

384 mol H2O

21.

2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

New problem: If 3.5 moles of oxygen gas are used up as ethane combusts completely, how many moles of carbon dioxide are produced?

a)

0.5 mol CO2

b)

0.57 mol CO2

c)

2.0 mol CO2

d)

3.0 mol CO2

e)

3.5 mol CO2

22.

2 C2H6 + 7 O2 → 4 CO2 + 6 H2O

New problem: How many moles of ethane (C2H6) are required to produce 13.5 moles of water from the above reaction?

a)

4.5 mol C2H6

b)

27 mol C2H6

c)

40.5 mol C2H6

d)

81 mol C2H6

e)

162 mol C2H6

23.

Which mole ratio tells how much aluminum oxide is produced from 3 moles of aluminum?


4Al + 3O2 → 2Al2O3

a)

3 mol Al/ 2 mol Al2O3

b)

2 mol Al2O3/ 4 mol Al

c)

4 mol Al/ 2 mol Al2O3

d)

2 mol Al2O3/ 3 mol Al

24.

What are the missing coefficients for the unbalanced equation below?

Cr(s) + Fe(NO3)2(aq) → Fe(s) + Cr(NO3)3(aq)

a)

2,3,3,2

b)

1,3,3,1

c)

2,3,2,3

d)

2,3,1,2

25.

What are the missing coefficients for the unbalanced equation below?

AlPO4 + Ba(OH)2 → Al(OH)3 + Ba3(PO4)2

a)

1,3,2,3

b)

2,3,2,3

c)

3,2,3,1

d)

2,3,2,1

26.

What is the mole ratio of Ba(OH)2 to AlPO4?

AlPO4 + Ba(OH)2 → Al(OH)3 + Ba3(PO4)2

a)

3 mol Ba(OH)2 / 2 mol AlPO4

b)

1 mol Ba(OH)2/ 1 mol AlPO4

c)

2 mol Ba(OH)2/ 3 mol AlPO4

d)

1 mol Ba(OH)2/ 3 mol AlPO4

27.

What is the mole ratio of Mg to MgCl2?

Mg(s) + HCl(aq) → MgCl2(aq) + H2(g)

a)

2 mol Mg/ 1 mol MgCl2

b)

1 mol Mg/ 2 mol MgCl2

c)

1 mol Mg/ 1 mol MgCl2

d)

2 mol Mg/ 2 mol MgCl2

28.

Mg(s) + HCl(aq) →MgCl2(aq) + H2(g)


The reaction of 2.5 mol of HCl will produce ______ mol of MgCl2.

a)

2.5

b)

1.25

c)

5.0

d)

1.0

29.

If there are 2 moles of oxygen available, which mole ratio will tells how much water is produced?


C3H8 +5O2 → 3CO2 + 4H2O

a)

4 mol H2O/ 5 mol O2

b)

5 mol O2/ 4 mol H2O

c)

2 mol O2/ 4 mol H2O

d)

4 mol O2/ 2 mol H2O

30.

If there are 10 moles of propane, C3H8, which mole ratio will tells how much oxygen is required for the reaction to take place?


C3H8 + 5O2 → 3CO2 + 4H2O

a)

1 mol C3H8/ 5 mol O2

b)

5 mol O2/ 1 mol C3H8

c)

5 mol O2/ 10 mol C3H8

d)

10 mol C3H8/ 5 mol O2

31.

N2 + 3H2 --> 2NH3

How many moles of NH3 is produced from 6 moles of N2?

a)

12 moles

b)

3 moles

c)

2 moles

d)

1.5 moles