Chapter 20:
Chemical Reactions and Energy
Practice Test
1.
Plants appear green because their leaves _____________.
a.
reflect green and yellow light
b.
absorb green and yellow light
c.
reflect red and blue light
d.
reflect UV light
Hint
2.
The _______________ in photosynthetic bacteria is/are found on membranes spread throughout the cells.
a.
Calories
b.
chlorophyll
c.
rhizomes
d.
grana
Hint
3.
One Calorie equals _____________.
a.
one BTU
b.
one joule
c.
one calorie
d.
one kilocalorie
Hint
4.
If C
w
equals 4.184 J/(gx
o
C), how much heat does 235 g of water gain when its temperature rises from 20.4
o
C to 39.6
o
C?
a.
0.438 kJ
b.
18.9 kJ
c.
6,630 J
d.
1.27 × 10
6
J
Hint
5.
These two elements catalyze reactions that remove pollutants in typical automobile catalytic converters.
a.
gold and silver
b.
iron and copper
c.
platinum and rhodium
d.
molybdenum and sodium
Hint
6.
In photosynthesis, ________________ are formed.
a.
fructose and nitrogen
b.
glucose and oxygen
c.
sucrose and water
d.
glucose and carbon dioxide
Hint
7.
An exothermic reaction has a ______________
H.
a.
zero
b.
high
c.
positive
d.
negative
Hint
8.
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.
-2.71 kJ/mol
c.
422 kJ/mol
d.
-527 kJ/mol
Hint
9.
Both exothermic and endothermic reactions require ________________.
a.
gaseous reactants
b.
precipitation
c.
solid products
d.
activation energy
Hint
10.
This device is used to measure the heat given off by chemical reactions.
a.
Dumas bulb
b.
colorimeter
c.
Erlenmeyer flask
d.
calorimeter
Hint
11.
The typical maximum efficiency of a coal-fired power plant is ______________.
a.
greater than 70%
b.
between 60% and 70%
c.
between 50% and 60%
d.
less than 40%
Hint
12.
An exothermic reaction is one that __________.
a. releases heat
b. produces smoke
c. neither releases nor absorbs heat
d. absorbs heat
Hint
13.
A reaction is always spontaneous in the forward direction when its ________________.
a.
energy decreases and entropy decreases
b.
energy decreases and entropy decreases
c.
energy increases and entropy increases
d.
energy decreases and entropy increases
Hint
14.
The two basic series of reactions that make up photosynthesis are called __________________.
a.
the light reactions and the Calvin cycle
b.
the dark reactions and the nitrogen cycle
c.
the light reactions and the carbon dioxide cycle
d.
the light reactions and the oxygen cycle
Hint
15.
The maximum energy reached during a reaction's uncatalyzed pathway is ______________ the maximum energy reached during its catalyzed pathway.
a.
slightly less than
b.
equal to
c.
much less than
d.
greater than
Hint
16.
The energy released or absorbed by a chemical reaction is symbolized ________________.
a.
H
reactants
b.
H
reactants
+ H
products
c.
H
products
d.
H
reaction
Hint
17.
The low entropy of living things is maintained partially by ____________.
a.
an increase in the entropy of the surroundings
b.
a decrease in the energy of the universe
c.
a decrease in the entropy of the surroundings
d.
an increase in the energy of the living things
Hint
18.
A coal-fired power plant converts ___________________.
a.
geothermal energy to electricity
b.
chemical energy to electricity
c.
electricity to wind energy
d.
kinetic energy to potential energy
Hint
19.
Any time energy is produced or is converted from one form to another, some is lost as _________.
a.
temperature
b.
heat
c.
mass
d.
hydrogen and oxygen
Hint
20.
Oil and natural gas are called _____________.
a.
esters
b.
fossil fuels
c.
polymers
d.
petroleum
Hint
