(a)
Interpretation:
The sign of the entropy change for the following process should be predicted and value of
Concept Introduction:
Entropy is defined as the ratio of thermal energy to the temperature which is unavailable for work done. It is also defined as the measure of disorder of molecule of a system. It is an extensive property and state function.
Entropy is related with the number of microstates for a system and microstate is defined as the number of ways for the system to be arranged. In different physical states, entropy depends upon the phase of the substance; the order of the entropy is given by:
The sign of the entropy should be predicted with the help of above information.
(a)
Answer to Problem 44E
Sign of entropy is negative as the randomness decreases.
Explanation of Solution
Given process is:
In this case, sign of entropy is negative as the number of moles of reactant in gaseous state is more in comparison to number of moles of product in gaseous state. Thus, relatively ordered precipitate (
The mathematical expression for the standard entropy value at room temperature is:
Where, n and p represents the coefficients of reactants and products in the balanced chemical equation.
The value of standard entropy for
The value of standard entropy for
The value of standard entropy for
The value of standard entropy for
Put the values, we get:
(b)
Interpretation:
The sign of the entropy change for the following process should be predicted and value of
Concept Introduction:
Entropy is defined as the ratio of thermal energy to the temperature which is unavailable for work done. It is also defined as the measure of disorder of molecule of a system. It is an extensive property and state function.
Entropy is related with the number of microstates for a system and microstate is defined as the number of ways for the system to be arranged. In different physical states, entropy depends upon the phase of the substance; the order of the entropy is given by:
The sign of the entropy should be predicted with the help of above information.
(b)
Answer to Problem 44E
Sign of entropy is positive.
Explanation of Solution
Given process is:
In this case, sign of entropy is positive as in this process, number of moles of products in gaseous state is more than the number of moles of reactants in gaseous state.
The mathematical expression for the standard entropy value at room temperature is:
Where, n and p represents the coefficients of reactants and products in the balanced chemical equation.
The value of standard entropy for
The value of standard entropy for
The value of standard entropy for
Put the values,
(c)
Interpretation:
The sign of the entropy change for the following process should be predicted and value of
Concept Introduction:
Entropy is defined as the ratio of thermal energy to the temperature which is unavailable for work done. It is also defined as the measure of disorder of molecule of a system. It is an extensive property and state function.
Entropy is related with the number of microstates for a system and microstate is defined as the number of ways for the system to be arranged. In different physical states, entropy depends upon the phase of the substance; the order of the entropy is given by:
The sign of the entropy should be predicted with the help of above information.
(c)
Answer to Problem 44E
Sign of entropyis hard to predict.
Explanation of Solution
Given process is:
In this case, number of moles of products in gaseous state is equal to the number of moles of reactants in gaseous state. Thus, it is hard to predict the sign of entropy.
The mathematical expression for the standard entropy value at room temperature is:
Where, n and p represents the coefficients of reactants and products in the balanced chemical equation.
The value of standard entropy for
The value of standard entropy for
The value of standard entropy for
The value of standard entropy for
Put the values,
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Chapter 10 Solutions
Chemical Principles
- Impure nickel, refined by smelting sulfide ores in a blast furnace, can be converted into metal from 99.90% to 99.99% purity by the Mond process. The primary reaction involved in the Mond process is Ni(s)+4CO(g)Ni(CO)4(g) a. Without referring to Appendix 4, predict the sign of S for the above reaction. Explain. b. The spontaneity of the above reaction is temperature-dependent. Predict the sign of Ssurr, for this reaction. Explain c. For Ni(CO)4(g), Hfo=607KJ/mol and S = 417 J/K mol at 298 K. Using these values and data in Appendix 4, calculate H and S for the above reaction. d. Calculate the temperature at which G = 0 (K = 1) for the above reaction, assuming that H and S do not depend on temperature. e. The first step of the Mood process involves equilibrating impure nickel with CO(g) and Ni(CO)4(g) at about 50C. The purpose of this step is to convert as much nickel as possible into the gas phase. Calculate the equilibrium constant for the above reaction at 50.C. f. In the second step of the Mood process, the gaseous Ni(CO)4 is isolated and heated to 227C. The purpose of this step is to deposit as much nickel as possible as pure solid (the reverse of the preceding reaction). Calculate the equilibrium constant for the preceding reaction at 227C. g. Why is temperature increased for the second step of the Mood process? h. The Mond process relies on the volatility of Ni(CO)4 for its success. Only pressures and temperatures at which Ni(CO)4 is a gas are useful. A recently developed variation of the Mood process carries out the first step at higher pressures and a temperature of l52C. Estimate the maximum pressure of Ni(CO)4(g) that can be attained before the gas will liquefy at 152C. The boiling point for Ni(CO)4 is 42C and the enthalpy of vaporization is 29.0 kJ/mol. [Hint: The phase change reaction and the corresponding equilibrium expression are Ni(CO)4(l)Ni(CO)4(g)K=PNi(CO)4 Ni(CO)4(g) will liquefy when the pressure of Ni(CO)4 is greater than the K value.]arrow_forwardUse S values to calculate the standard entropy change, rS0, for each of the following processes and comment on the sign of the change. (a) KOH(s) KOH(aq) (b) Na(g) Na(s) (c) Br2() Br2(g) (d) HCl(g) HCl(aq)arrow_forwardConsider two perfectly insulated vessels. Vessel 1 initially contains an ice cube at 0C and water at 0C. Vessel 2 initially contains an ice cube at 0C and a saltwater solution at 0C. Consider the process H2O(s) H2O(l). a. Determine the sign of S, Ssurr, and Suniv for the process in vessel 1. b. Determine the sign of S, Ssurr, and Suniv for the process in vessel 2. (Hint: Think about the effect that a salt has on the freezing point of a solvent.)arrow_forward
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