From 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 reaction,
will be:
1. | 1523.6 kJ mol-1 | 2. | -243.6 kJ mol-1 |
3. | -120.0 kJ mol-1 | 4. | 553.0 kJ mol-1 |
Entropy decreases during:
1. Crystallization of sucrose from solution
2. Rusting of iron
3. Melting of ice
4. Vaporization of camphor
Given the reaction:
\(2 \mathrm{Cl}(\mathrm{~g}) \rightarrow \mathrm{Cl}_2(\mathrm{~g})\)
What are the values of \(∆\mathrm{H}\) and \(∆\mathrm{S}\), respectively?
1. \(\Delta \mathrm{H}=0, \Delta \mathrm{~S}=-\mathrm{ve}\)
2. \(\Delta \mathrm{H}=0, \Delta \mathrm{~S}=0\)
3. \(\Delta \mathrm{H}=-\mathrm{ve}, \Delta \mathrm{~S}=-\mathrm{ve}\)
4. \(\Delta \mathrm{H}=+\mathrm{ve}, \Delta \mathrm{~S}=+\mathrm{ve}\)
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. \(25~ \mathrm{J}\)
1. | 120.9 kJ | 2. | 241.82 kJ |
3. | 18 kJ | 4. | 100 kJ |
Consider the following diagram for a reaction .
The nature of the reaction is-
1. Exothermic
2. Endothermic
3. Reaction at equilibrium
4. None of the above
The enthalpy of formation of all elements in their standard state is-
1. | Unity | 2. | Zero |
3. | Less than zero | 4. | Different for each element |
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 |
The amount of heat needed to raise the temperature of 60.0 g of aluminium from 35°C to 55°C would be:
(Molar heat capacity of Al is \(24\) \(J\) \(\text{mol}^{- 1}\) \(K^{- 1}\))
1. | \(1 . 07\) \(J\) | 2. | \(1 . 07\) \(kJ\) |
3. | \(106 . 7\) \(kJ\) | 4. | \(100 . 7\) \(kJ\) |
1. | 2. | ||
3. | 4. |