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Unit 9 Pre-Test



Please note:  All of the equations given are balanced.
 

 1. 

For the reaction
C  +  2 H2  -->  CH4
how many moles of hydrogen are required to produce 10 moles of methane (CH4)?
A
2
B
4
C
10
D
20
 

 2. 

For the reaction
2 H2  +  O2  -->  2 H2O
how many grams of water are produced from 6.00 moles of hydrogen?
A
2.00
B
6.00
C
54.0
D
108
 

 3. 

For the reaction
N2  +  3 H2  -->  2 NH3
how many moles of nitrogen are required to produce 18 moles of ammonia (NH3)?
A
9
B
18
C
27
D
36
 

 4. 

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
C
percent yield
B
mole ratio
D
actual yield
 

 5. 

In the reaction
6 CO2  +  6 H2O  -->  C6H12O6  +  6 O2
the mole ratio of water to oxygen is
A
2 : 1
B
1 : 1
C
3 : 2
D
6 : 8
 

 6. 

In the equation
2 KClO3  -->  2 KCl  +  3 O2
the number of moles of oxygen produced when 1.0 mole of potassium chlorate is decomposed is
A
1.0
B
1.5
C
2.0
D
3.0
 

 7. 

The number of moles of aluminum atoms reacting with 3 moles of oxygen molecules in the following balanced equation is
4 Al  +  3 O2  -->  2 Al2O3
A
1
B
2
C
3
D
4
 

 8. 

In the reaction
A  +  B  -->  C  +  D
if there is more reactant B than is required to react with all of reactant A, then
A
A is the limiting reactant
C
there is no limiting reactant
B
B is the limiting reactant
D
no product can be formed
 

 9. 

When the limiting reactant in a chemical reaction is completely used, the
A
excess reactants begin combining
C
reaction speeds up
B
reaction slows down
D
reaction stops
 

 10. 

In the reaction
2 C2H2 (g)  +  5 O2 (g)  -->  4 CO2 (g)  +  2 H2O (g)
what is the total number of moles of acetylene (C2H2) needed to completely react with 40. grams of oxygen?
A
0.25
B
0.50
C
0.75
D
1.0
 

 11. 

How many grams of water are needed to produce 22.4 grams of hydrogen bromide via the following reaction?                    2 Br2  +  2 H2O  -->  4 HBr  +  O2
A
201 g
B
4.98 g
C
9.97 g
D
2.49 g
 



 
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