NEET UG CHEMISTRY MCQ: THERMODYNAMICS

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Application +4 | -1

The entropy change associated with the conversion of 1 kg of ice at 273 K to water vapours at 383 K is (Specific heat of water liquid and water vapour are

4.2\,kJ\,{K^{ - 1}}\,k{g^{ - 1}}

and

20\,kJ\,{K^{ - 1}}\,k{g^{ - 1}}

; heat of liquid fusion and vapourisation of water are

334\,kJ\,k{g^{ - 1}}\mathrm{ }

and

2491\,kJ\,k{g^{ - 1}}

respectively).

(\log 273 = 2.436,\,\,\log 373 = 2.572,\,\,\log 383 = 2.583)

View answer and explanation

Correct option: A

9.26\,kJ\,\mathrm{ }\,k{g^{ - 1}}\,{K^{ - 1}}

Option A (

9.26\,kJ\,k{g^{ - 1}}\,{K^{ - 1}}

) is correct because it represents the total entropy change calculated by summing the entropy changes for each phase transition and heating step.

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