NEET UG CHEMISTRY MCQ: THERMODYNAMICS

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Analyzing +4 | -1

One mole of

\mathrm{CH}_3 \mathrm{COOH}

undergoes dimerization in vapour phase at

127^{\circ} \mathrm{C}

as:

2 \mathrm{CH}_3 \mathrm{COOH}(\mathrm{g}) \rightleftharpoons\left(\mathrm{CH}_3 \mathrm{COOH}\right)_2(\mathrm{~g})

if dimer formation is due to two

\mathrm{H}

-bonds involved in dimer, each of

33 \mathrm{~kJ}

stength and the degree of dimerisation of acetic acid

98.2 \%

. The change in standard entropy during dimerization is

View answer and explanation

Correct option: A

-104 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}

Option A (

-104 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}

) is correct because it represents the change in standard entropy during dimerization, calculated using the Gibbs-Helmholtz equation and the given enthalpy and temperature.

More Questions from THERMODYNAMICS

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The internal energy of one mole of a gas is: An ideal gas is allowed to expand both reversibly and irreversibly in an isolated system. If

{T_i}

is the initial temperature and

{T_f}

is the final temperature, which of the following statements is correct? For which of the process, ∆S is negative? The work done by a weightless piston in causing an expansion ∆V (at constant temperature), when the opposing pressure, P is variable, is given by: Assertion :- At constant pressure of the change

\mathrm{H}_2 \mathrm{O}(\mathrm{s}) \rightarrow \mathrm{H}_2 \mathrm{O}(\mathrm{g})

work done is negative.

Reason :- During phase transition work done is always negative. For the reaction,

\mathrm{X}_2 \mathrm{O_4(l}) \longrightarrow 2 \mathrm{XO}_2(\mathrm{g}), \Delta U=2.1 \mathrm{~kcal}, \Delta S=20 \mathrm{~cal} \mathrm{~K}^{-1}

300 \mathrm{~K}

. Hence,

\Delta G