Section 3.2
Changes in Matter
Practice Test
1.
How can the law of conservation of mass apply to a burning log, if all that remains of it is ash?
SC.B.1.4.2
a.
The law of conservation of mass applies to changes of state but not to chemical reactions.
b.
The ash has the same mass as the log, although a large percentage of it blows away.
c.
The masses of the gases and water vapor released into the air by the combustion reaction plus the mass of ash equal the mass of the log before burning.
d.
The law of conservation of mass applies to substitution and displacement reactions, but not to combustion reactions.
Hint
2.
In the following chemical reaction, how do you classify hydrogen and oxygen?
2H
2
+O
2
→ 2H
2
O
SC.A.1.4.4
a.
products
b.
chemical properties
c.
reactants
d.
physical changes
Hint
3.
How would you read the following chemical reaction?
2Cu+O
2
→ 2CuO
a.
copper and oxygen yield copper
II
oxide
b.
copper yields oxygen and copper
II
oxide
c.
oxygen yields copper and copper
II
oxide
d.
copper
II
oxide yields oxygen and copper
Hint
4.
How can you tell when the following reaction is balanced?
2Cu+O
2
→ 2CuO
SC.B.1.4.2
a.
volume of reactants = mass of products
b.
mass of the reactants = mass of products
c.
volume of reactants = volume of products
d.
mass of reactants = volume of products
Hint
5.
The statement, Mass can neither be created nor destroyed is the ____________.
SC.B.1.4.2
a.
law of conservation of mass
b.
law of gravity
c.
law of conservation of energy
d.
law of multiple proportions
Hint
