Gibbs Free Energy

IMPORTANT

Gibbs Free Energy: Overview

This topic covers concepts, such as, Gibbs Free Energy and Spontaneity, Gibbs Free Energy, Condition for Endothermic Non-spontaneous Process & Graph of Gibb's Function Vs Extent of Reaction etc.

Important Questions on Gibbs Free Energy

MEDIUM
IMPORTANT

The correct relationship between free energy and equilibrium constant K of a reaction is:                              

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IMPORTANT

Consider the following reaction occurring in automobile

2C8H18+25O2g16CO2g+18H2Og

the sign of  ΔH,  ΔS  and  ΔG would be:

EASY
IMPORTANT

Match list-I (Equations) with List-II (Type of processes) and select the correct option.
 

  List I   List II
  Equations   Type of processes
(1) Kp > Q (i) Non spontaneous
(2) Δ G o < RTInQ (ii) Equilibrium
(3) Kp = Q (iii) Spontaneous and endothermic
(4) T > Δ H Δ S (iv) Spontaneous

EASY
IMPORTANT

A chemical reaction will be spontaneous if it is accompanied by a decrease of

                               

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Identify the correct statement for change of Gibb’s energy for a system   (Δ G system )  at constant temperature and pressure:

                               

EASY
IMPORTANT

The enthalpy and entropy change for the reaction

  B r 2 (l)+C l 2 (g)2BrCl(g)

are   30kJmo l 1 and105J K 1 mo l 1  respectively. The temperature at which the reaction will be in equilibrium is

                               

MEDIUM
IMPORTANT

Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction?

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Standard enthalpy and standard entropy changes for the oxidation of ammonia at 298 K are -382.64kJmol1  and  145.6JK1mol1,  respectively. The standard Gibbs energy change for the same reaction at 298 K is:

                               

EASY
IMPORTANT

The entropy change in the fusion of one mole of a solid melting at  27°C (Latent heat of fusion,  2930Jmol1) is:

                               

HARD
IMPORTANT

What is the significance of point of minima in the plot between Gibbs energy and extent of the reaction?

HARD
IMPORTANT

What is the slope of the graph of Gibbs energy plotted against the extent of reaction?

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What is an endergonic reaction and plot it in a graph between Gibbs free energy and extent of reaction?

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What is an exergonic reaction and plot it in a graph between Gibbs free energy and extent of reaction?

HARD
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A plot of Gibbs energy of a reaction mixture against the extent of the reaction is : 

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What is the value of S at high temperature for exothermic non-spontaneous process?

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Which of the following condition is favourable for exothermic non-spontaneous process?

HARD
IMPORTANT

For an exothermic non-spontaneous process : 

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What is the effect of temperature on exothermic non-spontaneous reaction?

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IMPORTANT

What is the condition for non-spontaneous exothermic reaction?

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IMPORTANT

The maximum work (in kJ mol-1) that can be derived from complete combustion of 1 mole of CO at 298 K and 1 atm is [Standard enthalpy of combustion of CO=-283.0 kJ mol-1; standard molar entropies at 298 K: SO2=205.1 J mol-1, SCO=197.7 J mol-1. SCO2=213.7 J mol-1]