Assertion: Heat energy is completely transformed into work during the isothermal expansion of a gas. Reason: During an isothermal process, the changes in internal energy of a gas due to decrease in pressure is nullified by the changes due to increase in volume.

Question

Assertion: Heat energy is completely transformed into work during the isothermal expansion of a gas. Reason: During an isothermal process, the changes in internal energy of a gas due to decrease in pressure is nullified by the changes due to increase in volume. (A) It both Assertion and Reason are true and the Reason is a correct explanation of the Assertion (B) If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion (C) If Assertion is true but the Reason is false (D) If both Assertion and Reason is false

Tardigrade Admin · Accepted Answer

In an isothermal expansion, temperature is maintained constant so internal energy change is zero.

(Δ E = 0)

According to first law of thermodynamic,

Δ E = q + w;

q =

heat,

w =

work done

\Rightarrow q = - w

This shows that work is done by the system at the expense of heat absorbed.

Q. Assertion: Heat energy is completely transformed into work during the isothermal expansion of a gas. Reason: During an isothermal process, the changes in internal energy of a gas due to decrease in pressure is nullified by the changes due to increase in volume.

It both Assertion and Reason are true and the Reason is a correct explanation of the Assertion

If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion

If Assertion is true but the Reason is false

If both Assertion and Reason is false

In an isothermal expansion, temperature is maintained constant so internal energy change is zero. (ΔE=0) According to first law of thermodynamic, ΔE=q+w; q= heat, w= work done ⇒q=−w This shows that work is done by the system at the expense of heat absorbed.

Q. Assertion: Heat energy is completely transformed into work during the isothermal expansion of a gas.
Reason: During an isothermal process, the changes in internal energy of a gas due to decrease in pressure is nullified by the changes due to increase in volume.

In an isothermal expansion, temperature is maintained constant so internal energy change is zero. $(Δ E = 0)$

According to first law of thermodynamic,

$Δ E = q + w;$

$q =$ heat,

$w =$ work done

$\Rightarrow q = - w$

This shows that work is done by the system at the expense of heat absorbed.