The enthalpy of combustion of methane, graphite, and dihydrogen at 298 K are, –890.3 kJ mol1 , –393.5 kJ mol–1, and –285.8 kJ mol–1 respectively. The enthalpy of formation of CH4(g) is-

1. –74.8 kJ mol–1 2. –52.27 kJ mol–1
3. +74.8 kJ mol–1 4. +52.26 kJ mol–1
Subtopic:  Thermochemistry |
 67%
Level 2: 60%+
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 For the reaction A + B → C + D + q (kJ/mol), entropy change is positive. The reaction will be

1. Possible only at high temperature

2. Possible only at low temperature

3. Not possible at any temperature

4. Possible at any temperature

Subtopic:  Spontaneity & Entropy |
 59%
Level 3: 35%-60%
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The enthalpy of combustion of carbon to CO2 is –393.5 kJ mol-1. The amount of heat released upon formation of 35.2 g of CO2 from carbon and dioxygen gas would be:

1. –393.5 kJ mol–1 2. –314.8 kJ mol–1
3. +314.8 kJ mol–1 4. –320.5 kJ mol–1
Subtopic:  Thermochemistry |
 76%
Level 2: 60%+
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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. \(\Delta \mathrm{H}=+\mathrm{ve}, \Delta \mathrm{~S}=+\mathrm{ve}\)

Subtopic:  Spontaneity & Entropy |
 79%
Level 2: 60%+
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What is a necessary condition for an adiabatic process to occur?

1. ∆T = 0

2. ∆P = 0

3. q = 0

4. w = 0

Subtopic:  Thermodynamics' Properties and process |
 91%
Level 1: 80%+
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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
Subtopic:  Thermodynamics' Properties and process |
 82%
Level 1: 80%+
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U° for combustion of methane is –x kJ mol–1.

The value of H° for the same reaction would be:

1. = U°
2. > U°
3. < U°
4. =0

Subtopic:  Enthalpy & Internal energy |
 66%
Level 2: 60%+
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701 J of heat is absorbed by a system and 394 J of work is done by the system. The change in internal energy for the process is:

1. 307 J 2. -307 J
3. 1095 J 4. -701 J
Subtopic:  First Law of Thermodynamics |
 83%
Level 1: 80%+
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The reaction of cyanamide, NH2CN (s) with dioxygen, was carried out in a bomb calorimeter, and ∆U was found to be -742.7 kJ mol-1 at 298 K.
\(\small{\mathrm{NH}_2 \mathrm{CN}(\mathrm{s})+\frac{3}{2} \mathrm{O}_2(\mathrm{g}) \rightarrow \mathrm{N}_2(\mathrm{g})+\mathrm{CO}_2(\mathrm{g})+\mathrm{H}_2 \mathrm{O}(\mathrm{l})}\)

The enthalpy change for the reaction at 298 K would be:

1. -741.3 kJ mol-1
2. + 753.9 kJ mol-1
3. + 772. 7 kJ mol-1
4. -845. 1 kJ mol-1

Subtopic:  Enthalpy & Internal energy |
 76%
Level 2: 60%+
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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. \(100 . 7\) \(kJ\)
Subtopic:  Thermodynamics' Properties and process |
 69%
Level 2: 60%+
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