Which of the following is not an endothermic reaction?
1. Combustion of methane
2. Decomposition of water
3. Dehydrogenation of ethane or ethylene
4. Conversion of graphite to diamond
Assume each reaction is carried out in an open container. For which of the following reactions will
1.
2.
3.
4.
What is the value of ∆H for the reaction 2Al + Cr₂O₃ → 2Cr + Al₂O₃, knowing that the enthalpies of
formation of Al₂O₃ and Cr₂O₃ are –1596 kJ and –1134 kJ, respectively?
1. | –1365 kJ | 2. | 2730 kJ |
3. | –2730 kJ | 4. | –462 kJ |
Hydrolysis of sucrose is given by the following reaction
Sucrose + H2O Glucose + Fructose
If the equilibrium constant (Kc) is 21013 at 300 K, the value of at the same temperature will be:
1. 8.314 J mol–1 K–1300 Kln (21013)
2. 8.314 J mol–1 K–1300 Kln (31013)
3. –8.314 J mol–1 K–1300 Kln (41013)
4. –8.314 J mol–1 K–1300 Kln (21013)
For the reaction, , the value of ∆H and ∆S are respectively:
1.
2.
3.
4.
When 4 g of iron is burnt to ferric oxide at a constant pressure, 29.28 kJ of heat is evolved.
The enthalpy of formation of ferric oxide will be-
(At. mass of Fe = 56) ?
1. 81.98 kJ
2. 819.8 kJ
3. 40.99 kJ
4. +819.8 kJ
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. |