GATE Overflow for GATE BT - Recent activity in Classical thermodynamics and Bioenergetics

Edited: GATE BT 2026 | Question: 40

Tue, 17 Mar 2026 07:12:06 +0000

An enzyme-catalyzed reaction is found to have $\Delta \mathrm{G}=-100 \mathrm{~kJ} \mathrm{~mol}^{-1}$. Which of the following statements about this reaction is/are true?

The rate of the reaction cannot be predicted
The rate of the reaction is high
The rate of the reaction is low
The reaction is irreversible

Edited: GATE BT 2026 | Question: 24

Tue, 17 Mar 2026 07:02:05 +0000

Given below is the Gibbs free energy change ( $\Delta \mathrm{G}$ ) in kilo Joules per electron equivalent ( $\mathrm{kJ} \mathrm{e}^{-} \mathrm{eq}^{-1}$ ) at pH $7.0$, of organic and inorganic half reactions.

Acetate synthesis:
\[
\frac{1}{8} \mathrm{CO}_{2}+\frac{1}{8} \mathrm{HCO}_{3}^{-}+\mathrm{H}^{+}+\mathrm{e}^{-} \rightarrow \frac{1}{8} \mathrm{CH}_{3} \mathrm{COO}^{-}+\frac{3}{8} \mathrm{H}_{2} \mathrm{O} \quad \Delta \mathrm{G}=27.4 \mathrm{~kJ} \mathrm{e}^{-} \mathrm{eq}^{-1}
\]

Reduction reaction:
\[
\frac{1}{4} \mathrm{O}_{2}+\mathrm{H}^{+}+\mathrm{e}^{-} \rightarrow \frac{1}{2} \mathrm{H}_{2} \mathrm{O} \quad \Delta \mathrm{G}=-78.72\mathrm{~kJ} \mathrm{e}^{-} \mathrm{eq}^{-1}
\]

The free energy change of acetate oxidation to $\mathrm{CO}_{2}, \mathrm{H}_{2} \mathrm{O}$ and $\mathrm{HCO}_{3}^{-}$ is $\_\_\_\_$ $\mathrm{kJ} \mathrm{e}^{-} \mathrm{eq}^{-1}$. (rounded off to two decimal places)

Edited: GATE BT 2026 | Question: 18

Tue, 17 Mar 2026 06:57:11 +0000

Which of the following drugs inhibit(s) $\text{ATP-ADP}$ translocase?

Oligomycin
Atractyloside
Amytal
Bongkrekic acid

Edited: GATE BT 2025 | Question: 19

Sun, 01 Jun 2025 19:12:04 +0000

For a mechanically reversible isobaric process taking place in a closed system involving $5$ moles of an ideal gas, the temperature increases from an initial value of $300 \: K$ to a final value of $450 \: K$. If the specific heat capacity at constant volume $\left(C_{\mathrm{v}}\right)$ is given as $12.5 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$ and gas constant is $8.314 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$, the amount of heat transferred to the system will be $\_\_\_\_\_$ $\mathrm{J}$.

(Round off to the nearest integer)

Recategorized: GATE BT 2024 | Question: 3

Mon, 21 Apr 2025 15:50:32 +0000

Which one of the following statements is correct in the context of thermodynamics?

In a closed system, neither mass nor energy is transferred across the system boundary
In a closed system, both mass and energy can be transferred across the system boundary
The total energy of the system is the sum of kinetic and potential energies
In a closed system, only energy can be transferred across the system boundary and not mass

Recategorized: GATE BT 2024 | Question: 47

Mon, 21 Apr 2025 15:48:29 +0000

The free energy change of ATP hydrolysis at $25^{\circ} \mathrm{C}$ is $-32.2 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The free energy change for hydrolysis of $\alpha$-glycerophosphate to glycerol is $-8.2 \mathrm{~kJ} \mathrm{~mol}^{-1}$ at $25^{\circ} \mathrm{C}$. Using the above information, the free energy change for the formation of $\alpha$-glycerophosphate from glycerol and ATP is $\_\_\_\_\_\_\_\_$ $\mathrm{kJ} \mathrm{mol}^{-1}$ (Answer in integer).

Recategorized: GATE BT 2022 | Question: 25

Mon, 21 Apr 2025 15:42:29 +0000

For a pure species, the slope of the melting line
$$\frac{dP}{dT} \; \text{at} \; -2 \; ^{\circ} \textrm{C} \; \text{is} -5.0665 \times 10^{6} \text{Pa K}^{-1}.$$
The difference between the molar volumes of the liquid and solid phase at $-2 ^{\circ} \text{C}$ is $-4.5\times 10^{6} \; \text{m}^{3} \text{mol}^{-1}.$

The value of the latent heat of fusion (rounded off to nearest integer) is __________ $\text{J} \; \text{mol}^{-1}.$

Recategorized: GATE BT 2022 | Question: 51

Mon, 21 Apr 2025 15:41:04 +0000

Consider a piston-cylinder assembly shown in the figure below. The walls of the cylinder are insulated. The cylinder contains $1$ mole of an ideal gas at $300 \; \text{K}$ and the piston is held initially at the position $\text{z}_{1}$ using a stopper. After the stopper is removed, the piston suddenly rises against atmospheric pressure $(1.013\times 10^{5} \; \text{Pa})$ to the new position $\text{z}_{2}$ where it is held by another stopper.

The heat capacity $(C_{v})$ of the gas is $12.5 \; \text{J mol}^{-1} \text{K}^{-1}.$ The cross-sectional area of the cylinder is $10^{-3} \text{m}^{2}.$ Assume the piston is weightless and frictionless.

If $\text{z}_{2} – \text{z}_{1} =1\; \text{m},$ the final temperature of the gas (rounded off to nearest integer) is _____________$\text{K}.$

Recategorized: GATE BT 2021 | Question: 24

Mon, 21 Apr 2025 15:39:58 +0000

A system consists of two reactors, connected by a valve. The first reactor $(R1)$ contains an ideal gas $A$ of volume $5\: L$ and the second reactor $(R2)$ has an ideal gas $B$ of volume $10\: L$. Initially, the valve is closed and pressure $P$ in $R1$ and $R2$ are $9$ and $6 \textit{ atm}$, respectively. Later, when the valve is opened, the system reaches equilibrium. If the temperature $T$ of both the reactors is maintained constant, the final equilibrium pressure in $\textit{atm}$ of the system is _____________

Recategorized: GATE2020: 26

Mon, 21 Apr 2025 15:38:34 +0000

A block of ice at $0 \:^{\circ}C$ is supplied heat at a constant rate to convert ice to superheated steam. Which one of the following trajectories correctly represents the trend of the temperature of the system with time? Assume that the Specific heat of $H_{2}O$ is not a function of temperature.

Recategorized: GATE2020: 14

Mon, 21 Apr 2025 15:36:50 +0000

Which of the following are energy transducing membranes?

Plasma membrane of bacteria
Inner membrane of chloroplasts
Inner membrane of mitochondria

$P$ and $Q$ only
$P$ and $R$ only
$Q$ and $R$ only
$P, Q$ and $R$

Recategorized: GATE BT 2015 | Question: 60

Mon, 21 Apr 2025 15:25:44 +0000

The standard free energy change $(\Delta G' ^\circ)$ for ATP hydrolysis is $-30 kJ \cdot \text{mole}^{-1}$. The $\textit{in vivo}$ concentrations of ATP, ADP and $P_i$ in $E \textit{.coli}$ are $7.90, 1.04$ and $7.90$ mM, respectively. When $E\text{.coli}$ cells are cultured at $37 ^\circ C$, the free energy change $(\Delta G)$ for ATP hydrolysis $\textit{in viva}$ is _______ $kJ \cdot \text{mole}^{-1}$.