Section 20.1
Energy Changes in Chemical Reactions
Practice Test
1.
An exothermic reaction is one that _______________.
a.
absorbs heat
b.
neither releases nor absorbs heat
c.
produces smoke
d.
releases heat
Hint
2.
An instant cold pack utilizes an _____________________ reaction.
a.
endothermic dissolution
b.
exothermic combustion
c.
endothermic combustion
d.
exothermic synthesis
Hint
3.
Both exothermic and endothermic reactions require ________________.
a.
activation energy
b.
gaseous reactants
c.
solid products
d.
precipitation
Hint
4.
Oil and natural gas are called _____________.
a.
esters
b.
fossil fuels
c.
petroleum
d.
polymers
Hint
5.
The energy released or absorbed by a chemical reaction is symbolized ________________.
a.
H
reaction
b.
H
reactants
c.
H
reactants
+ H
products
d.
H
products
Hint
6.
The maximum energy reached during a reaction's uncatalyzed pathway is ______________ the maximum energy reached during its catalyzed pathway.
a.
greater than
b.
equal to
c.
slightly less than
d.
much less than
Hint
7.
A system's ____________ describes its degree of disorder.
a.
entropy
b.
enthalpy
c.
energy
d.
volume
Hint
8.
A reaction is always spontaneous in the forward direction when its ________________.
a.
energy decreases and entropy increases
b.
energy increases and entropy increases
c.
energy increases and entropy decreases
d.
energy decreases and entropy decreases
Hint
9.
An exothermic reaction has a ______________
H.
a.
high
b.
negative
c.
positive
d.
zero
Hint
10.
Burning 1.00 g of a subtance with a molar mass of 42.0 g/mol raises the temperature of 100.0 g of water from 17.2
o
C to 47.2
o
C. What is the heat of combustion of the substance?
a.
-890 kJ/mol
b.
-527 kJ/mol
c.
-2.71 kJ/mol
d.
422 kJ/mol
Hint
