Question

Match the thermodynamic processes given under Column I with the expressions given under Column II.

$\begin{array}{cc}\text{Column I}& \text{Column II}\\ \text{(A) Freezing of water at 273 K and 1 atm}& \text{(P)}q=0\\ \text{(B) Expansion of 1 mol of an ideal gas into a}& \text{(Q)}w=0\\ \text{vacuum under isolated conditions}& \\ \text{(C) Mixing of equal volumes of two ideal gases at}& \text{(R)}\Delta S_{sys}<0\\ \text{constant temperature and pressure in an}& \\ \text{isolated container}& \\ \text{(D) Reversible heating of}{H}_2\left(g\right)\text{at 1 atm from}& \text{(S)}\Delta U=0\\ \text{300 K to 600 K, followed by reversible cooling}& \\ \text{to 300 K at 1 atm}& \\ & \text{(T)}\Delta G=0\end{array}$

• A. $(A-R,T)(B-P,Q,S)(C-P,Q,S)(D-P,Q,S,T)$
• B. $(A-R)(B-P,Q,S)(C-S)(D-P,Q,R,S,T)$
• C. $(A-P,Q,S)(B-Q)(C-P,Q,S)(D-P,Q,S,T)$
• D. $(A-R,T)(B-P,S)(C-P,S)(D-P,Q,R,S,T)$

Answer 1

The correct option is A $(A-R,T)(B-P,Q,S)(C-P,Q,S)(D-P,Q,S,T)$

(A) $H_{2}O\left(l\right)\to H_{2}O\left(s\right)$ at 273 K. & 1 atm
$\Delta H=-ve=q$
$\Delta S_{sys}<0,\Delta G=0$
$w\ne 0$ (as water expands on freezing), $\Delta U\ne 0$

(B) Free expansion of ideal gas.
$q=0$
$w=0$
$\Delta U=0$
$\Delta S_{sys}>0$
$\Delta G<0$

(C) Mixing of equal volume of ideal gases at constant pressure & temp in an isolated container
$q=0,w=0,\Delta U=0,\Delta S_{sys}>0,\Delta G<0$

(D) $H_2\left(g\right)300\text{K}\underset{\text{Heating, 1 atm}}{\overset{\text{Reversible}}{\to }}600\text{K}\underset{\text{Cooling, 1 atm}}{\overset{\text{Reversible}}{\to }}300\text{K}$

$q=0,w=0,\Delta U=0,\Delta G=0,\Delta S_{sys}=0$