An ideal gas expands in volume from \(1×10^{–3} m^3\) to \(1×10^{–2} m^3\) at 300 K against a constant pressure of 1×105 Nm-2. The work done is:
1. | –900 J | 2. | –900 kJ |
3. | 270 kJ | 4. | 900 kJ |
The enthalpies of combustion of carbon and carbon monoxide are -393.5 and -283 kJ mol-1 respectively. The enthalpy of the formation of carbon monoxide per mole is:
1. 110.5 kJ
2. 676.5 kJ
3. -676.5 kJ
4. -110.5 kJ
The enthalpy changes for the following processes are listed below :
Cl2 (g) → 2Cl(g), 242.3 kJ mol-1
I2 (g) → 2I (g), 151.0 kJ mol-1
ICI (g) → I(g) + Cl(g), 211.3 kJ mol-1
I2 (s) → I2 (g), 62.76 kJ mol-1
Given that the standard states for iodine and chlorine are I2 (s) and Cl2 (g), the standard enthalpy of formation of ICI (g) is :
1. -14.6 kJ mol-1
2. -20.8 kJ mol-1
3. +16.8 kJ mol-1
4. +244.8 kJ mol-1
\((\Delta H-\Delta U)\) for the formation of carbon monoxide (CO) from its elements at 298 K is :
(R = 8.314 JK-1 mol-1)
1. -1238.78 J mol-1
2. 1238.78 J mol-1
3. -2477.57 J mol-1
4. 2477.57 J mol-1
If a reaction is non-spontaneous at the freezing point of water but is spontaneous at the boiling point of water, then:
\(\Delta H\) | \(\Delta S\) | |
1. | +ve | +ve |
2. | -ve | -ve |
3. | -ve | +ve |
4. | +ve | -ve |
If at 298 K the bond energies of C-H, C-C, C = C and H-H bonds are respectively 414, 347, 615, and 435 kJ mol–1, the value of enthalpy change for the reaction at 298 K will be:
\(\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}_{2}(g)+\mathrm{H}_{2}(g) \longrightarrow \mathrm{H}_{3} \mathrm{C}-\mathrm{CH}_{3}(g)\)
1. +250 kJ
2. –250 kJ
3. +125 kJ
4. –125 kJ
The internal energy change when a system goes from state A to B is 40 k J/mol . If the system goes from A to B by a reversible path and returns to state A by an irreversible path, what would be the net change in internal energy?
1. 40 kJ
2. > 40kJ
3. < 40 kJ
4. zero
Assuming that water vapor is an ideal gas, the internal energy change (∆U) when 1 mol of water is vaporized at 1 bar pressure and 100°C, will be:
(Given: Molar enthalpy of vaporization of water at 1 bar and 373 K = 41 kJ mol–1 and R = 8.3 J mol–1 K–1)
1. 4.100 kJ mol–1
2. 3.7904 kJ mol–1
3. 37.904 kJ mol–1
4. 41.00 kJ mol–1
Standard entropy of and are and respectively. For the reaction, to be at equilibrium, the temperature will be
1. 500 K
2. 750 K
3. 1000 K
4. 1250 K
1. | - 610 kJ mol-1 | 2. | - 850 kJ mol-1 |
3. | +120 kJ mol-1 | 4. | +152 kJ mol-1 |