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. | \(25~ \mathrm{J}\) |
Assuming each reaction is carried out in an open container,
Reaction that shows ΔH=ΔE is :
1.
2.
3.
4.
The bond energy of H—H and Cl-Cl is 430 kJ
mol-1 and 240 kJ mol-1 respectively and ΔHf for HCl is -90 kJ mol-1. The bond enthalpy of HCl is:
1. 290
2. 380
3. 425
4. 245
1. 93 kJ mol-1
2. - 245 kJ mol-1
3. -93 kJ mol-1
4. 245 kJ mol-1
1. 1.968 V
2. 2.0968 V
3. 1.0968 V
4. 0.0968 V
1. ΔH = 0 and ΔS < 0
2. ΔH > 0 and ΔS > 0
3. ΔH < 0 and ΔS < 0
4. ΔH > 0 and ΔS < 0
The values of ΔH and ΔS for the given reaction are 170 kJ and 170 JK-1, respectively.
C(graphite) + CO2(g)→2CO(g)
This reaction will be spontaneous at:
1. 710 K
2. 910 K
3. 1110 K
4. 510 K
Give the following bond energies:
H—H bond energy: 431.37 kJ mol-1
C=C bond energy: 606.10 kJ mol-1
C—C bond energy: 336.49 kJ mol-1
C—H bond energy: 410.50 kJ mol-1
Enthalpy for the following reaction will be:
Standard entropies of X2, Y2 and XY3 are 60, 40 and 50JK-1mol-1 respectively. For the reaction
to be at equilibrium, the temperature should be:
1. 750 K
2. 1000 K
3. 1250 K
4. 500 K