Thermodynamics - Physical Chemistry - Chemistry Previous Year Questions

The reaction in which \(\Delta H=\Delta U\) is

When the same quantity of heat is absorbed by a system at two different temperatures \(T_1\) and \(T_2\), such that \(T_1>T_2\), change in entropies are \(\Delta S_1\) and \(\Delta S_2\) respectively. Then

The work done when 2 moles of an ideal gas expands rèversibly and isothermally from a volume of \(1 \mathrm{~L}\) to \(10 \mathrm{~L}\) at \(300 \mathrm{~K}\) is (\(R=0.0083 \mathrm{~kJ} \mathrm{~K} \mathrm{~mol}^{-1}\))

A gas at a pressure of \(2 \mathrm{~atm}\) is heated from \(25^{\circ} \mathrm{C}\) to \(323^{\circ} \mathrm{C}\) and simultaneously compressed of \(\frac{2}{3}\)rd of its original value. Then the final pressure is

Lattice enthalpy for \(\mathrm{NaCl}\) is \(+788 \mathrm{~kJ} \mathrm{~mol}^{-1}\) and \(\Delta H_{\text {hyd }}^{\circ}=-784 \mathrm{~kJ} \mathrm{~mol}^{-1}\). Enthalpy of solution of \(\mathrm{NaCl}\) is

Temperature of \(25^{\circ} \mathrm{C}\) in Fahrenheit and Kelvin scale respectively are

From the diagram $(Z)=\frac{V_{\text {real }}}{V_{\text {ideal }}}$

$\Delta_r H$ for the reaction, $C \rightarrow A$ is

Given below are two statements.

Statement-I : Adiabatic work done is positive when work is done on the system and internal energy of the system increases.

Statement - II : No work is done during free expansion of an ideal gas.

In the light of the above statements, choose the correct answer from the options given below.

Which one of the following reactions has $\Delta \mathrm{H}=\Delta \mathrm{U}$ ?

Identify the incorrect statements among the following:

(a) All enthalpies of fusion are positive

(b) The magnitude of enthalpy change does not depend on the strength of the intermolecular interactions in the substance undergoing phase transformations.

(c) When a chemical reaction is reversed, the value of $\Delta \mathrm{rH}^{\circ}$ is reversed in sign.

(d) The change in enthalpy is dependent of path between initial state (reactants) and final state (products)

(e) For most of the ionic compounds, $\Delta_{\text {sol }} \mathrm{H}^{\circ}$ is negative