Thermodynamics - Physical Chemistry PYQ | Chemistry

Two flasks \(A\) and \(B\) have equal volumes. \(A\) is maintained at \(300 \mathrm{~K}\) and \(B\) at \(600 \mathrm{~K}\). Equal masses of \(\mathrm{H}_2\) and \(\mathrm{CO}_2\) are taken in flasks \(A\) and \(B\) respectively. Find the ratio of total KE of gases in flask \(A\) to that of \(B\).

When the temperature of 2 moles of an ideal gas is increased by 20\(^\circ\)C at constant pressure. Find the work involved in the process.

If a chemical reaction is known to be non-spontaneous at 298 K but spontaneous at 350 K, then which among the following conditions is true for the reaction?

When an ideal gas expands isothermally from \(5 \mathrm{~m}^3\) to \(10 \mathrm{~m}^3\) at \(25^{\circ} \mathrm{C}\) against a constant pressure of \(10^7 \mathrm{~Nm}^{-2}\), then the work done on the gas is

Find the approximate value of \((\Delta H-\Delta U)\) in \(\mathrm{Jmol}^{-1}\), for the formation of CO from its elements at \(298 \mathrm{~K} .\left(R=8.314 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}\right)\)

For the reaction, \(\mathrm{H}_2 \mathrm{O}(l) \longrightarrow \mathrm{H}_2 \mathrm{O}(\mathrm{g})\) at \(T=100^{\circ} \mathrm{C}\) and \(p=1 \mathrm{~atm}\), choose the correct option.

From the following plots, find the correct option.

Observe the following properties : Volume, enthalpy, density, temperature, heat capacity, pressure and internal energy. The number of extensive properties in the above list is

Match the following.

Which of the following expression is correct?

Identify the reaction/process in which the entropy increases.

State \(1 \rightleftharpoons\) State \(2 \rightleftharpoons\) State 3 \(\left(\begin{array}{l}T=300 \mathrm{~K} \\ p=15 \mathrm{bar} \\ 1 \mathrm{~mol}\end{array}\right)\left(\begin{array}{l}T=300 \mathrm{~K} \\ p=10 \mathrm{bar} \\ 1 \mathrm{~mol}\end{array}\right)\left(\begin{array}{l}T=300 \mathrm{~K} \\ p=5 \mathrm{bar} \\ 1 \mathrm{~mol}\end{array}\right)\)

Above shows a cyclic process. Calculate the total work done during one complete cycle. [Assume a single step to reach the next state].

Identify the correct statements from the following.

I. At 0 K , the entropy of pure crystalline materials approach zero.

II. Entropy for the process, \(\mathrm{H}_2 \mathrm{O}(\mathrm{l}) \longrightarrow \mathrm{H}_2 \mathrm{O}(\mathrm{g})\) decreases.

III. Gibb's energy is a state function.

Use the data from table to estimate the enthalpy of formation of \(\mathrm{CH}_3 \mathrm{CHO}\).

Identify the incorrect statements form the following.

I. $ \Delta S_{\text {pum }}=\left(\Delta S_{\text {nal }}+\Delta S_{\text {um }}\right) $

II. $A(\bar{i} \rightarrow A(\phi)$ : For this process entropy change decreases.

III. Entropy units are $\mathrm{JK} \mathrm{mol}^{-1}$.

Given below are two statements :

Statement I For isothermal irreversible change of an ideal gas, $q=-w=p_{\text {ext }}\left(V_{\text {final }}-V_{\text {initial }}\right)$

Statement II For adiabatic change, $\Delta U=w_{\text {adiabatic }}$

The correct answer is :