Chemistry · Thermodynamics & Thermochemistry
JEE Advanced 2023 — Paper 1 — Question 42
In a one-litre flask, 6 moles of A undergoes the reaction (g). The progress of product formation at two temperatures (in Kelvin), and , is shown in the figure: If and , then the value of is . [ and are standard Gibb's free energy change for the reaction at temperatures and , respectively.]

Answer: 8
Numerical answer — enter this value.
Step-by-step solution
\Delta G_1^\circ &= -RT_1 \ln 2 \\ \Delta G_2^\circ &= -RT_2 \ln \frac{1}{2} = RT_2 \ln 2 \\ \Delta G_2^\circ - \Delta G_1^\circ &= RT_2 \ln 2 + RT_1 \ln 2 \quad \therefore T_1 = 2T_2 \\ \Delta G_2^\circ - \Delta G_1^\circ &= RT_2 \ln 2 + R(2T_2) \ln 2 \\ &= 3RT_2 \ln 2 = RT_2 \ln 2^3 \\ &= RT_2 \ln 8 \\ RT_2 \ln 8 &= RT_2 \ln X \\ \text{So, } X &= 8 \end{aligned}$$
Answer key and solution verified before publishing.
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- Exam
- JEE Advanced 2023
- Paper
- Paper 1
- Subject
- Chemistry
- Chapter
- Thermodynamics & Thermochemistry
- Topic
- Gibbs Free Energy and the Third Law of Thermodynamics