NEET UG CHEMISTRY MCQ: THERMODYNAMICS

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Which among the following equations
represents the first law of thermodynamics
under isobaric conditions?

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Correct option: A

\Delta \mathrm{U}=\mathrm{q}_{\mathrm{p}}-\mathrm{P}_{\mathrm{ex}} \cdot \Delta \mathrm{V}

The correct answer is A (

\Delta \mathrm{U}=\mathrm{q}_{\mathrm{p}}-\mathrm{P}_{\mathrm{ex}} \cdot \Delta \mathrm{V}

) because it represents the first law of thermodynamics under isobaric (constant pressure) conditions, where the change in internal energy equals the heat added at constant pressure minus the work done due to volume change.

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