A English

Standard free energy Questions in English

Class 11 Chemistry · 6-1.Equilibrium (Chemical Equilibrium) · Standard free energy

104+

Questions

English

Language

100%

With Solutions

Showing 4 of 104 questions in English

101
DifficultMCQ
Calculate $\Delta G^\circ$ for the reaction, $CH_4(g) + H_2(g) \rightarrow C_2H_6(g)$ at $298 \text{ K}$, given $K_p = 2 \times 10^{17}$ and $R = 8.314 \text{ J K}^{-1} \text{mol}^{-1}$.
A
$-64.695 \text{ kJ mol}^{-1}$
B
$-98.716 \text{ kJ mol}^{-1}$
C
$-44.08 \text{ kJ mol}^{-1}$
D
$-58.78 \text{ kJ mol}^{-1}$

Solution

(B) The relationship between standard Gibbs free energy change and equilibrium constant is given by: $\Delta G^\circ = -RT \ln K_p$.
Given: $R = 8.314 \text{ J K}^{-1} \text{mol}^{-1}$, $T = 298 \text{ K}$, $K_p = 2 \times 10^{17}$.
$\Delta G^\circ = -8.314 \times 298 \times \ln(2 \times 10^{17})$.
$\Delta G^\circ = -8.314 \times 298 \times (\ln 2 + \ln 10^{17})$.
$\Delta G^\circ = -8.314 \times 298 \times (0.693 + 17 \times 2.303)$.
$\Delta G^\circ = -8.314 \times 298 \times (0.693 + 39.151) = -8.314 \times 298 \times 39.844$.
$\Delta G^\circ \approx -98716 \text{ J mol}^{-1} = -98.716 \text{ kJ mol}^{-1}$.
102
DifficultMCQ
The equilibrium constant for a reaction is $100$. What will be the value of standard Gibbs energy change at $298 \text{ K}$? $(R = 8.314 \text{ J K}^{-1} \text{mol}^{-1})$
A
-$11.411$ \text{ kJ/mol}
B
-$5.744$ \text{ kJ/mol}
C
-$570.584$ \text{ kJ/mol}
D
-$57.058$ \text{ kJ/mol}

Solution

(A) The relationship between standard Gibbs energy change $(\Delta G^\circ)$ and equilibrium constant $(K)$ is given by: $\Delta G^\circ = -RT \ln K$.
Given: $R = 8.314 \text{ J K}^{-1} \text{mol}^{-1}$, $T = 298 \text{ K}$, $K = 100$.
$\Delta G^\circ = -8.314 \times 298 \times \ln(100)$.
Since $\ln(100) = 2.303 \times \log_{10}(100) = 2.303 \times 2 = 4.606$.
$\Delta G^\circ = -8.314 \times 298 \times 4.606 \text{ J/mol}$.
$\Delta G^\circ = -11411.4 \text{ J/mol} = -11.411 \text{ kJ/mol}$.
103
EasyMCQ
Identify the relation between the standard Gibbs free energy change $\Delta G^{\circ}$ and the equilibrium constant $K_c$ for a chemical reaction.
A
$\Delta G^{\circ} = RT \ln K_c$
B
$-\Delta G^{\circ} = \frac{RT}{\ln K_c}$
C
$\Delta G^{\circ} = \frac{\ln K_c}{RT}$
D
$-\Delta G^{\circ} = RT \ln K_c$

Solution

(D) The relationship between the standard Gibbs free energy change $\Delta G^{\circ}$ and the equilibrium constant $K_c$ is given by the equation:
$\Delta G^{\circ} = -RT \ln K_c$
Multiplying both sides by $-1$, we get:
$-\Delta G^{\circ} = RT \ln K_c$
Therefore, option $D$ is correct.
104
DifficultMCQ
Calculate the standard Gibbs energy change $(\Delta G^\circ)$ for a gaseous reaction at $298 \text{ K}$ if the equilibrium constant $K_p$ is $3.5 \times 10^{17}$ and the gas constant $R$ is $8.314 \text{ J K}^{-1} \text{mol}^{-1}$.
A
-$100.1 \text{ kJ mol}^{-1}$
B
-$79.5 \text{ kJ mol}^{-1}$
C
-$71.4 \text{ kJ mol}^{-1}$
D
-$89.5 \text{ kJ mol}^{-1}$

Solution

(A) The formula for standard Gibbs energy change is $\Delta G^\circ = -RT \ln K_p$.
Given: $R = 8.314 \text{ J K}^{-1} \text{mol}^{-1}$, $T = 298 \text{ K}$, $K_p = 3.5 \times 10^{17}$.
Using the relation $\ln x = 2.303 \log_{10} x$:
$\Delta G^\circ = -2.303 \times R \times T \times \log_{10} K_p$.
$\Delta G^\circ = -2.303 \times 8.314 \times 298 \times \log_{10}(3.5 \times 10^{17})$.
$\log_{10}(3.5 \times 10^{17}) = \log_{10}(3.5) + 17 \approx 0.544 + 17 = 17.544$.
$\Delta G^\circ = -2.303 \times 8.314 \times 298 \times 17.544 \approx -100135 \text{ J mol}^{-1}$.
Converting to kJ: $\Delta G^\circ \approx -100.1 \text{ kJ mol}^{-1}$.

6-1.Equilibrium (Chemical Equilibrium) — Standard free energy · Frequently Asked Questions

1Are these 6-1.Equilibrium (Chemical Equilibrium) questions useful for JEE and NEET?

Yes. All questions in this section are mapped to JEE Main and NEET exam patterns. Previous year questions from JEE Main, NEET, GUJCET and state-level exams are included with full solutions.

2Can I switch to Hindi or Gujarati for these questions?

Yes. Use the language tabs in the hero section or the sidebar to view the same questions and solutions in English, Hindi or Gujarati.

3How do I generate a question paper from this subtopic?

Use the Vedclass Exam Paper Generator — select the chapter and subtopic, set difficulty, and generate Sets A, B, C, D automatically. First 3 chapters of every subject are free.

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D papers from this chapter in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo
For Teachers & Institutes

Generate a 6-1.Equilibrium (Chemical Equilibrium) Exam Paper in 2 Minutes

Select subtopic & difficulty — Sets A, B, C, D auto-generated with No Repeat logic.

First 3 chapters of every subject are free — no payment required.