A process among the following shows decrease in entropy is :
1. \(2 \text H \left(g\right)\rightarrow\text H_{2} \left(g\right)\)
2. Evaporation of water
3. Expansion of a gas at a constant temperature
4. Sublimation of solid to gas
Under the isothermal condition, a gas at \(300 \mathrm{~K}\) expands from \(0.1 \mathrm{~L}\) to \(0.25 \mathrm{~L}\) against a constant external pressure of 2 bar. The work done by the gas is:
| 1. | \(30 ~\mathrm {J} \) | 2. | \(-30 ~\mathrm{J} \) |
| 3. | \(5~ \mathrm{kJ}\) | 4. | \(25~ \mathrm{J}\) |
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. | \(–900~ kJ\) |
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. | \(T_C>T_A\) |
Hydrolysis of sucrose is given by the following reaction
Sucrose + H2O Glucose + Fructose
If the equilibrium constant (Kc) is 21013 at 300 K, the value of at the same temperature will be:
1. 8.314 J mol–1 K–1300 Kln (21013)
2. 8.314 J mol–1 K–1300 Kln (31013)
3. –8.314 J mol–1 K–1300 Kln (41013)
4. –8.314 J mol–1 K–1300 Kln (21013)
| 1. | \(\Delta_{\mathrm{r}} \mathrm{H}>0\) and \(\Delta_{\mathrm{r}} \mathrm{S}<0 \) | 2. | \(\Delta_{\mathrm{r}} \mathrm{H}<0\) and \( \Delta_{\mathrm{r}} \mathrm{S}>0 \) |
| 3. | \(\Delta_{\mathrm{r}} \mathrm{H}<0 \) and \(\Delta_{\mathrm{r}} \mathrm{S}<0 \) | 4. | \(\Delta_{\mathrm{r}} \mathrm{H}>0\) and \( \Delta_{\mathrm{r}} \mathrm{S}>0\) |
The correct option for free expansion of an ideal gas under adiabatic condition is:
1. and
2. and
3. and
4. and
If for a certain reaction is 30 kJ mol–1 at 450 K, the value of (in JK–1 mol–1) for which the same reaction will be spontaneous at the same temperature is:
| 1. | 70 | 2. | –33 |
| 3. | 33 | 4. | –70 |
At standard conditions, if the change in the enthalpy for the following reaction is –109 kJ mol–1
H2(g)+Br2(g)2HBr(g) and the bond energy of H2 and Br2 is 435 kJ mol–1 and 192 kJ mol–1 respectively, what is the bond energy (in kJ mol–1) of HBr?
| 1. | 368 | 2. | 736 |
| 3. | 518 | 4. | 259 |
Which of the following options correctly represents the relationship between \(C_p \text { and } C_V\) for one mole of an ideal gas?
| 1. | \(C_P=R C_V \) | 2. | \(C_V=RC_P \) |
| 3. | \(C_P+C_V=R \) | 4. | \(C_{{P}}-{C}_{{V}}={R}\) |