NEET UG CHEMISTRY MCQ: THERMODYNAMICS

1 Hard

1 of 1

Application +4 | -1

1.0 \mathrm{~kcal}

of heat is added to

1.2 \mathrm{~L}

\mathrm{O}_2

in a cylinder at constant pressure of

1 \mathrm{~atm}

, the volume increases to

1.5 \mathrm{~L}

. Calculate

\Delta \mathrm{U}

and

\Delta \mathrm{H}

of the process.

(1 \mathrm{~L}-\mathrm{atm}=100 \mathrm{~J}, 1 \mathrm{~cal}=4.2 \mathrm{~J})

View answer and explanation

Correct option: A

\Delta \mathrm{U}=4170 \mathrm{~J}; \Delta \mathrm{H}=1 \mathrm{~kcal}

Option A (ΔU=4170 J; ΔH=1 kcal) is correct because it involves calculating the change in internal energy and enthalpy using the given heat added and volume change at constant pressure.

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