A gas at initial temperature \(T\) undergoes sudden expansion from volume \(V\) to \(2V.\) Then,
| 1. | the process is adiabatic. |
| 2. | the process is isothermal. |
| 3. | the work done in this process is zero. |
| 4. | the entropy in the process does not change. |
| 1. | \(W_1<W_2<W_3\) | 2. | \(W_2<W_1=W_3\) |
| 3. | \(W_2<W_1<W_3\) | 4. | \(W_1>W_2>W_3\) |
A piston filled with 0.04 mol of an ideal gas expands reversibly from 50.0 mL to 375 mL at a constant temperature of 37.0ºC. As it does so, it absorbs 208 J of heat. The values of q and w for the process will be-
(R = 8.314 J/mol K) (ln 7.5 = 2.01)
| 1. | q = +208 J, w = -208 J | 2. | q = -208 J, w = -208 J |
| 3. | q = -208 J, w = + 208 J | 4. | q = +208 J, w = + 208 J |
Entropy decreases during:
1. Crystallization of sucrose from solution
2. Rusting of iron
3. Melting of ice
4. Vaporization of camphor
For the following given equations and values, determine the enthalpy of reaction at 298 K for the reaction:
C2H4(g) + 6F2(g) 2CF4(g) + 4HF(g)
H2(g) + F2(g) 2HF(g) = -537 kJ
C(s) + 2F2(g) CF4(g) =-680 kJ
2C(s) + 2H2(g) C2H4(g) = 52 kJ
1. –1165 kJ
2. –2486 kJ
3. +1165 kJ
4. +2486 kJ
(298K) of methanol is given by the chemical equation:
1. \(\mathrm{C}(\text { diamond })+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{H}_{2(\mathrm{~g})} \rightarrow \mathrm{CH}_3 \mathrm{OH}_{(\mathrm{l})}\)
2. \(\mathrm{CH}_{4(\mathrm{~g})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CH}_3 \mathrm{OH}_{(\mathrm{g})}\)
3. \(\mathrm{CO}_{(\mathrm{g})}+2 \mathrm{H}_{2(\mathrm{~g})} \rightarrow \mathrm{CH}_3 \mathrm{OH}_{(\mathrm{l})}\)
4. \(\mathrm{C}(\text { graphite })+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{H}_{2(\mathrm{~g})} \rightarrow \mathrm{CH}_3 \mathrm{OH}_{(\mathrm{l})}\)
Reversible expansion of an ideal gas under isothermal and adiabatic conditions are shown in the figure:
ABIsothermal expansion
ACAdiabatic expansion
Which of the following options is not correct?
| 1. | \(\Delta S_{\text {isothermal }}>\Delta S_{\text {adiabatic }} \) | 2. | \(T_A=T_B \) |
| 3. | \(W_{\text {isothermal }}>W_{\text {adiabatic }} \) | 4. | \(T_C>T_A\) |
What is the amount of work done by an ideal gas, if the gas expands isothermally from \(10^{-3}~m^3\) to \(10^{-2}~m^3\) at \(300~K\)against a constant pressure of \(10^{5}~Nm^{-2}\)?
| 1. | \(+270 ~kJ\) | 2. | \(–900 ~J\) |
| 3. | \(+900 ~kJ\) | 4. | \(–900~ kJ\) |
The volume versus temperature graph for two moles of monoatomic gas is shown in the figure. The ratio of work done by the gas to the heat absorbed by it in the process \(A\) to \(B\) is:
| 1. | \(\dfrac{1}{2}\) | 2. | \(\dfrac{2}{5}\) |
| 3. | \(\dfrac{3}{7}\) | 4. | \(\dfrac{3}{5}\) |
1. \(2R\)
2. \(3R\)
3. \(5R\)
4. \(7R\)