(a)
Interpretation:
The sign of ΔS0 for the reaction should be predicted.
Concept Introduction :
Entropy is a measure of molecular disorder or randomness. Higher the randomness, higher the systemβs entropy. In solids, atoms and molecules are restricted to a fixed position. In liquid phase, atoms and molecules are free to move around each other, but remain in relatively close proximity. In gas phase, atoms and molecules are free to move in much greater volume than liquid. So, entropy of substances differs as follows
(a)
Answer to Problem 154MP
Negative.
Explanation of Solution
Number of moles of substances in gas phase has reduced. So, the randomness of the system decreases. So, ΔS0 will be negative.
(b)
Interpretation:
The sign of ΔSsurr for the reaction should be predicted if the spontaneity of the reaction is temperature-dependent.
Concept Introduction :
ΔSsurr − entropy change of the surrounding
ΔH − enthalpy change
T − temperature
(b)
Answer to Problem 154MP
Positive.
Explanation of Solution
Since ΔS0 is negative, ΔH0 also should be negative for the reaction to be spontaneous. Therefore, ΔSsurr is positive.
(c)
Interpretation:
ΔS0 and ΔH0 for the preceding reaction should be calculated.
Concept Introduction :
(c)
Answer to Problem 154MP
Explanation of Solution
(d)
Interpretation:
The temperature at which
Concept Introduction:
(d)
Answer to Problem 154MP
Explanation of Solution
(e)
Interpretation:
The equilibrium constant for the reaction at 50 0C should be calculated.
Concept Introduction:
(e)
Answer to Problem 154MP
Explanation of Solution
(f)
Interpretation:
The equilibrium constant for the reaction at 227 0C should be calculated.
Concept Introduction:
(f)
Answer to Problem 154MP
Explanation of Solution
(g)
Interpretation:
The reason for increasing the temperature in the second step of Mondβs process should be explained.
Concept Introduction:
Le Chatelierβs principle states that if a change occurred in an equilibrium system, the equilibrium shifts in such a way that the system counteracts that change.
(g)
Answer to Problem 154MP
When temperature is increased, backward reaction is more favorable and more solid nickel will form.
Explanation of Solution
Enthalpy change of the forward reaction is negative. So, forward reaction is an exothermic reaction. The purpose of the second step of Mondβs process is to deposit as much nickel as possible as pure solid. So, the equilibrium should shift to left. When the temperature increases, the equilibrium shifts left in order to reduce the temperature of the system. So, rate of the backward reaction increases forming more solid of nickel.
(h)
Interpretation:
The maximum pressure of Ni(CO)4 should be estimated.
Concept Introduction:
The change in Gibbs free energy is calculated as follows:
Also,
(h)
Answer to Problem 154MP
Explanation of Solution
at 42 0C (the boiling point)
At 152 0C;
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Chapter 10 Solutions
CHEM.PRINC.W/OWL2+REBATE+2 SUPPL.>IP<
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