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 )
The enthalpy of formation of are
–110 kJ , – 393 kJ , 81 kJ and 9.7 kJ respectively.
The value of for the reaction would be-
. The standard enthalpy of formation of gas in the above reaction would be-
1. | -92.4 J (mol)-1 | 2. | -46.2 kJ (mol)-1 |
3. | +46.2 J (mol)-1 | 4. | +92.4 kJ (mol)-1 |