WorksheetsEntropy Review
Total questions: 15
Worksheet time: 14mins
Name
Class
Date
1.
What phase change brings an increase in entropy?
a)
g->s
b)
l->s
c)
l->g
d)
g->l
2.
Which interval represents the heat of reaction for the reaction?
a)
A
b)
B
c)
D
d)
E
3.
As NaCl dissolves according to the equation
NaCl(s) → Na+(aq) + Cl-(aq), the entropy of the system
NaCl(s) → Na+(aq) + Cl-(aq), the entropy of the system
a)
Increases
b)
Decreases
c)
Remains the same
4.
Spontaneous reactions are driven by
a)
increasing enthalpy and increasing entropy.
b)
decreasing enthalpy and decreasing entropy.
c)
increasing enthalpy and decreasing entropy.
d)
decreasing enthalpy and increasing entropy.
5.
Solid magnesium dissolves in a hydrochloric acid, releasing hydrogen gas and heat from a solution of magnesium chloride. What is the sign on ΔH for this reaction?
a)
Negative because it is exothermic
b)
Negative because it is endothermic
c)
Positive because it is exothermic
d)
Positive because it is endothermic
6.
When ammonium nitrate dissolves in water, the solution gets cold. Which is true?
a)
Reaction is ENDOTHERMIC with positive ΔH
b)
Reaction is ENDOTHERMIC with -ΔH
c)
Reaction is EXOTHERMIC with a -ΔH
d)
Reaction is EXOTHERMIC with +ΔH
7.
Which one of these would result in a decrease in entropy?
a)
A solid solute dissolves in water.
b)
A gas is released.
c)
A liquid freezes.
d)
A liquid boils.
8.
Solid magnesium dissolves in a hydrochloric acid, releasing hydrogen gas and heat from a solution of magnesium chloride. What is the sign on ΔS for this reaction?
a)
Negative because it is becoming more ordered.
b)
Negative because it is becoming more disordered.
c)
Positive because it is becoming more ordered.
d)
Positive because it is becoming more disordered.
9.
Solid magnesium dissolves in a hydrochloric acid, releasing hydrogen gas and heat from a solution of magnesium chloride. What is the sign on ΔG for this reaction?
a)
Negative because it is spontaneous
b)
Negative because it is nonspontaneous
c)
Positive because it is spontaneous
d)
Positive because it is nonspontaneous
10.
The reaction
A + 2 B2 + C --> CAB4
has an enthalpy change of -104 kJ and a change in entropy of -60.8 J/K at 30 °C. What is the free energy and spontaneity of the reaction?
A + 2 B2 + C --> CAB4
has an enthalpy change of -104 kJ and a change in entropy of -60.8 J/K at 30 °C. What is the free energy and spontaneity of the reaction?
a)
-85.6 kJ, spontaneous
b)
-18.3 kJ, not spontaneous
c)
+18.3 kJ, spontaneous
d)
+85.6 kJ, not spontaneous
11.
A reaction has a positive ΔH and a positive ΔS. Which of the following is true?
a)
It will be spontaneous at all temperatures.
b)
It will be nonspontaneous at all temperatures.
c)
It will be spontaneous at low temperatures.
d)
It will be spontaneous at high temperatures.
12.
True/False: The rate of a chemical reaction is unrelated to the spontaneity of the reaction.
a)
True
b)
False
13.
Endergonic reactions require:
a)
an input of energy
b)
a release of energy
c)
do not change energy
14.
For which of these processes is the value of ΔH expected to be positive?
1. The temperature increases when calcium chloride dissolves in water.
2. Steam condenses to liquid water
3. Water boils
4. Dry ice sublimates
1. The temperature increases when calcium chloride dissolves in water.
2. Steam condenses to liquid water
3. Water boils
4. Dry ice sublimates
a)
4 only
b)
1 only
c)
3 and 4 only
d)
2 and 3 only
15.
Which type of reaction increases entropy?
a)
Endergonic
b)
Nonspontaneous
c)
Synthesis
d)
Exergonic
100 %
