GATE BT topic:classical-thermodynamics-bioenergetics PYQs & Answers — Page 2

Questions 11–19 of 19. Imported answers require independent review unless marked reviewed.

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 K and the piston is held initially at the position

using a stopper. After the stopper is removed, the piston suddenly rises against atmospheric pressure (

Pa) to the new position

where it is held by another stopper.

The heat capacity (

) of the gas is 12.5 J mol

. The cross-sectional area of the cylinder is

. Assume the piston is weightless and frictionless.

m, the final temperature of the gas (rounded off to nearest integer) is __________ K.

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Under standard temperature (

) and pressure (

) conditions, 128 g of an ideal gas molecule

occupies a volume of 1 L. The gas molecule

obeys the relationship

and

are universal gas constant and ideal gas volume, respectively. The molecule

Your answerChoose one option.

CO₂

H₂

N₂

O₂

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A system consists of two reactors, connected by a valve. The first reactor (

) contains an ideal gas

of volume

and the second reactor (

) has an ideal gas

of volume

. Initially, the valve is closed and pressure

and

are

and

, respectively. Later, when the valve is open, the system reaches equilibrium. If the temperature

of both the reactors is maintained constant, the final equilibrium pressure in

of the system is ________.

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Solvents A and B are completely immiscible. Solute S is soluble in both these solvents. 100 g of S was added to a container which has 2 kg each of A and B. The solute is 1.5 times more soluble in solvent A than in solvent B. The mixture was agitated thoroughly and allowed to reach equilibrium. Assuming that the solute has completely dissolved, the amount of solute in solvent A phase is ____________ g.

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A block of ice at 0 °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 H₂O is not a function of temperature.

Your answerChoose one option.

Diagram for Biotechnology question 26 (figure 2)

Diagram for Biotechnology question 26 (figure 3)

Diagram for Biotechnology question 26 (figure 4)

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The concentrations of ATP, ADP and inorganic phosphate in a cell are 2.59, 0.73 and 2.72 mM, respectively. Under these conditions, free energy change for the synthesis of ATP at 37 °C is __________ kJ/mol (round off to 2 decimal places).

Given: free energy change for ATP hydrolysis under standard conditions is -30.5 kJ/mol and R = 8.315 kJ/mol.K

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The mitochondrial electron transfer chain oxidizes NADH with oxygen being the terminal electron acceptor. The redox potentials for the two half-reactions are given below:

The free energy change associated with the transfer of electrons from NADH to O₂ is __________ kJ/mol (round off to 2 decimal places).

Given: F = 9650 C/mol.

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The difference in concentrations of an uncharged solute between two compartments is 1.6-fold. The energy required for active transport of the solute across the membrane separating the two compartments is ______ cal mol⁻¹ (rounded off to the nearest integer). (R = 1.987 cal mol⁻¹ K⁻¹, T = 37 °C)

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The interaction energy E between two spherical particles is plotted as a function of the distance (r) between them. When

, where

is a constant, the net force between the spherical particles is repulsive. When

, they attract via van der Waals attraction. Which one of the following plots correctly represents the interaction energy between the above two particles?

Your answerChoose one option.