For the reaction, , the value of ∆H and ∆S are respectively:
1.
2.
3.
4.
Match the following process with entropy change:
Reaction | Entropy change | ||
A. | A liquid vaporizes | 1. | |
B. | Reaction is non-spontaneous at all temperatures and is positive | 2. | |
C. | Reversible expansion of an ideal gas | 3. |
Codes:
A | B | C | |
1. | 2 | 3 | 1 |
2. | 1 | 2 | 3 |
3. | 1 | 3 | 2 |
4. | 3 | 2 | 1 |
Match the following parameters with a description for spontaneity.
\(\Delta\) (Parameters) \(\Delta r\ H^⊝\) \(\Delta r\ S^⊝\)\(\Delta r\ G^⊝\) | Description | ||
A. | + – + | 1. | Non-spontaneous at high temperature |
B. | – – + at high T | 2. | Spontaneous at all temperatures |
C. | – + – | 3. | Non-spontaneous at all temperatures |
Codes:
A | B | C | |
1. | 3 | 1 | 2 |
2. | 1 | 2 | 3 |
3. | 1 | 3 | 2 |
4. | 3 | 2 | 1 |
Assertion (A): | A liquid crystallizes into a solid and is accompanied by a decrease in entropy. |
Reason (R): | In crystals, molecules organize in an ordered manner. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) is False but (R) is True. |
Thermodynamics is not concerned about:
1. | Energy changes involved in a chemical reaction. |
2. | The extent to which a chemical reaction proceeds. |
3. | The rate at which a reaction proceeds. |
4. | The feasibility of a chemical reaction. |
The correct statement among the following is:
1. | The presence of reacting species in a covered beaker is an example of an open system. |
2. | There is an exchange of energy as well as matter between the system and the surroundings in a closed system. |
3. | The presence of reactants in a closed vessel made up of copper is an example of a closed system. |
4. | The presence of reactants in a thermos flask or any other closed insulated vessel is an example of a closed system. |
If the volume of a gas is reduced to half from its original volume, then the specific heat will:
1. | Reduce to half | 2. | Be Doubled |
3. | Remain constant | 4. | Increase four times |
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 |
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. | \(100 . 7\) \(kJ\) |
The enthalpy of formation of are–110 kJ , – 393 kJ , 81 kJ and 9.7 kJ \(\text{mol}^{- 1}\) respectively.
The value of \(\left(\Delta\right)_{r} H\) for the reaction would be:
\(\mathrm{N_{2} O_{4 \left(g\right)} + 3 \left(CO\right)_{\left(g\right)} \rightarrow N_{2} O_{\left(g\right)} + 3 \left(CO\right)_{2 \left(g\right)}}\)
1. | \(- 777 . 7\) \(kJ\) \(\text{mol}^{- 1}\) | 2. | \(\) \(+ 777 . 7\) \(kJ\) \(\text{mol}^{- 1}\) |
3. | \(\) \(+ 824 . 9\) \(kJ\) \(\text{mol}^{- 1}\) | 4. | \(-\) \(345 . 4\) \(kJ\) \(\text{mol}^{- 1}\) |