Thermodynamics of Equilibrium

IMPORTANT

Thermodynamics of Equilibrium: Overview

This topic covers concepts, such as, Relationship between Equilibrium Constant (K) & Reaction Quotient (Q) and Gibbs Free Energy Change (ΔG) etc.

Important Questions on Thermodynamics of Equilibrium

MEDIUM
IMPORTANT

The Haber’s process for the formation of  NH 3 at 298 K is N2+3H22NH3;ΔH=46.0KJ. Which of the following is the correct statement?

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

                               

EASY
IMPORTANT

A schematic plot of ln   K eq versus inverse of temperature for a reaction is shown below

Question Image

The reaction must be –

HARD
IMPORTANT

In a one-litre flask, 6 moles of A undergoes the reaction A( g)P( g). The progress of product formation at two temperatures (in Kelvin), T1 and T2, is shown in the figure:

Question Image

If T1=2T2 andΔG2o-ΔG1o=RT2lnx , then the value of x is
[ ΔG1o and ΔG2o are standard Gibb's free energy change for the reaction at temperatures T1 and T2, respectively.]

MEDIUM
IMPORTANT

What is the (approx) partial pressure of CO2at equilibrium at 427°C?

CaCO3sCaOs+CO2g   G=-13.5 kJ

MEDIUM
IMPORTANT

Select the correct option about ΔG for the following reaction

H2Ol(2 atm,373 K)H2Og (2 atm,373 K)

(Given: 0.0821×373×ln2=21.23 L atm, molar volume of water at 2 atm, 373 K=18 ml)

MEDIUM
IMPORTANT

ΔGo=+ 63.3 kJ for the reaction Ag2CO3s2Ag+aq+CO3-2aq
the thermodynamic equilibrium constant at 25oC is:

EASY
IMPORTANT

Which of the following is correct at equilibrium?

HARD
IMPORTANT

Select the graph which can be used to determine standard free energy of the reaction given below:

CaCO3(s)CaO(s)+CO2(g)
Assume that the reaction is at equilibrium.

EASY
IMPORTANT

Among the following set of conditions, which condition necessarily holds true for a non-feasible process?
(Where, K=equilibrium constant)

EASY
IMPORTANT

Calculate the temperature given that the value of Kc = 103 and ΔGf° of A, B and C are 100, 200 and 500 kJ/mol  and the reactants A and B is in equilibrium with C.

MEDIUM
IMPORTANT

Calculate G for the following change, if vapour pressure of water is 0.01 atm at 27ºC.

H2Ol, 0.01 atm, 27°CH2Og, 0.01 atm, 27°C

EASY
IMPORTANT

Which is correct for the combustion reaction occurring in an automobile is 2C8H18(s) + 25O2(g)  16CO2(g) + 18H2O(g)

MEDIUM
IMPORTANT

The value of Kc for the following reaction at 298 K is:

2NH3(g)+CO2(g)NH2CONH2(aq)+2H2O()  

Given, standard Gibbs energy change ΔG° at the given temperature is -13.6kJ/mol-1

EASY
IMPORTANT

For the following reaction,

C2H6(g)C2H4(g)+H2(g)

the kp=0.05 atm. What is the value of ΔG° of the reaction at 627C?

EASY
IMPORTANT

For a spontaneous chemical reaction, the value of G° must be negative and the value of Keq must be greater than __

Given: G° = -RT ln Keq

MEDIUM
IMPORTANT

Consider that for a hypothetical reaction, ΔH° and ΔS° are -30 kJ mol-1 and -100 JK-1mol-1 at 300K. What is the equilibrium constant for the reaction at 298 K?

EASY
IMPORTANT

For a hypothetical reaction, ΔH=-30 kJ mol-1 and ΔS=-100 J K-1 mol-1. At what temperature (in Celsius), the reaction is at equilibrium?

MEDIUM
IMPORTANT

For the given reaction, concentrations are given as: [NH3] is 0.05 M and [NH4+]=[OH-]=0.002 M in the presence of excess water. What is the value of ΔGKJ/mol at 298 K at some non-equilibrium condition?

Δ G Reaction  = + 2 6 · 8 1  KJ  mol
NH3aq+H2OlNH4+aq+OH-aq

MEDIUM
IMPORTANT

Consider the curve between ln K and 1/T. Which plot will be correct for exothermic reaction?