Name: 
 

Old Unit 8 Test Questions



 

 1. 

The reaction         Pb(NO3)2  +  2 KI  -->  PbI2  +  2 KNO3      is a
a.
double replacement reaction
c.
synthesis reaction
b.
single replacement reaction
d.
decomposition reaction
 

 2. 

In what kind of reaction do two elements combine to form one compound?
a.
double replacement reaction
c.
synthesis reaction
b.
single replacement reaction
d.
decomposition reaction
 

 3. 

The substances to the left of the arrow (“yield” sign) in a chemical equation are called
a.
products
b.
reactants
c.
molecules
d.
compounds
 

 4. 

With which type of chemical reaction must you use the activity series to determine if the reaction will actually take place?
a.
double replacement reaction
c.
synthesis reaction
b.
single replacement reaction
d.
decomposition reaction
 

 5. 

In what type of reaction does one compound produce two elements?
a.
double replacement reaction
c.
synthesis reaction
b.
single replacement reaction
d.
decomposition reaction
 

 6. 

What is the general term for the number written below the line with a formula, such as the “2” in CO2?
a.
reactant
b.
product
c.
coefficient
d.
subscript
 

 7. 

What observation of a chemical reaction would indicate that a gas is being formed?
a.
color change
c.
a precipitate is formed
b.
heat is given off
d.
bubbling and fizzing
 

 8. 

The substances to the right of the arrow (“yield” sign) in a chemical equation are called
a.
products
b.
reactants
c.
molecules
d.
compounds
 

 9. 

In writing an equation that produces hydrogen gas, the correct representation of hydrogen gas is
a.
H
b.
2 H
c.
H2
d.
OH
 

 10. 

What is the whole number that appears in front of a formula in a chemical equation?
a.
subscript
b.
superscript
c.
ratio
d.
coefficient
 

 11. 

Which of the following is the correct equation for the formation of carbon dioxide from carbon and oxygen?
a.
C  +  2 O  -->  CO2
c.
C  +  O2  -->  CO2
b.
CO2  -->  C  +  O2
d.
2 C  +  O  -->  CO2
 

 12. 

Which observation does NOT indicate that a chemical reaction has occurred?
a.
change in the total mass of substances
c.
evolution of heat and light
b.
formation of a precipitate
d.
production of a gas
 

 13. 

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
 

 14. 

The equation     A  +  BC  -->  AC  +  B     is the general equation for a
a.
double replacement reaction
c.
decomposition reaction
b.
single replacement reaction
d.
combustion reaction
 

 15. 

When the equation     Fe3O4  +  Al  -->  Al2O3  +  Fe     is correctly balanced, what is the coefficient of Fe?
a.
3
b.
4
c.
6
d.
9
 



 
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