Q. No.For the reaction : \(A_2 + B_2 \xrightarrow {500~K} 2 AB\) : where, Log K = 2.2
Calculate the value of x:
1. 70
2. 60
3. 50
4. 80
| \(\mathrm{H}_{\mathrm{f}}{ }^0 \text { (KJ/mole) }\) | \(\mathrm{S}_{\mathrm{f}}^0(\mathrm{~J} / \mathrm{K} \text {-mole })\) | |
| AB | 32 | 240 |
| \(A_2\) | 6 | 224 |
| \(B_2\) | x | 238 |
Calculate the value of x:
1. 70
2. 60
3. 50
4. 80
Subtopic: Enthalpy & Internal energy | Spontaneity & Entropy |
Level 3: 35%-60%
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4 kg of water is heated from \(4^\circ C\) to \(20^\circ C\) at constant pressure \(10^5\) Pa, so that density changes from \(1000~kg/m^3\) to \(998 ~kg/m^3.\) Then find \(\Delta U\) (in Joules ):
[Given: \(C_s\) of \(H_2O=4.2 \) Joule /gm.K]
1. 268799.2 Joule
2. 368900 Joule
3. 168400 Joule
4. 578876.8 Joule
[Given: \(C_s\) of \(H_2O=4.2 \) Joule /gm.K]
1. 268799.2 Joule
2. 368900 Joule
3. 168400 Joule
4. 578876.8 Joule
Subtopic: Enthalpy & Internal energy |
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Level 2: 60%+
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| List-I | List-II (KJ) |
||
| (I) | Isothermal reversible (1mole ideal gas, T = 300K, \(2dm^3\) to \(20dm^3 ) \)calculate |w| | (A) | 8.32 |
| (II) | Isothermal irreversible \([3KPa, 1m^3 ~\text{to} ~3m^3 ]\) calculate |w| | (B) | 6 |
| (III) | 1 mole gas undergoes constant pressure process in which change in temperature is 400K, Cp = 5R/2, calculate \(\Delta H\) | (C) | 4 |
| (IV) | 1 mole ideal gas having Cv=3R/2 and \(\Delta T\) = 320K, calculate \(\Delta U\) | (D) | 5.74 |
Select the correct match
1. I-A: II-B: III-D: IV-C
2. I-D: II-B: III-A: IV-C
3. I-B: II-A: III-C: IV-D
4. I-A: II-B: III-C: IV-D
Subtopic: Thermodynamics' Properties and process | Enthalpy & Internal energy |
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The heat capacity of a bomb calorimeter is \(5 \mathrm{~kJ} / \mathrm{K}.\) When combustion of octane takes place in presence of excess \(\mathrm{O}_2\), the temperature rises by \(5^{\circ} \mathrm{C}.\) The value of \(\Delta \mathrm{H}_{\text {combustion }}\) in \(\mathrm{kJ }\) is:
| 1. | 20 | 2. | 25 |
| 3. | 30 | 4. | 35 |
Subtopic: Enthalpy & Internal energy | Cp & Cv |
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Given that the values of ΔH° and ΔS° for a process/reaction are 77.2 kJ and 48 J/K, respectively, calculate the value of log 1/k when the temperature is 300 K.
1. 11
2. 5
3. 15
4. 100
1. 11
2. 5
3. 15
4. 100
Subtopic: Enthalpy & Internal energy |
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Level 3: 35%-60%
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Calculate the internal energy of 2 moles of an ideal monoatomic gas at 300 K.
(Given R=8.31 J/mol K)
1. 7421 J
2. 7479 J
3. 7589 J
4. 7531 J
(Given R=8.31 J/mol K)
1. 7421 J
2. 7479 J
3. 7589 J
4. 7531 J
Subtopic: Enthalpy & Internal energy |
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For the combustion of CH₃OH, the reaction \(CH_3OH(l)+\frac32O_2(g)\rightarrow CO_2(g)+2H_2O(l).\) is carried out, and the heat of reaction measured in a bomb calorimeter at 27°C is 786 kJ. If the heat of combustion of the above reaction is \(-x~kJ,\), calculate the value of \(x\).
1. 787
2. 797
3. 778
4. 810
1. 787
2. 797
3. 778
4. 810
Subtopic: Enthalpy & Internal energy |
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The enthalpy of combustion of propane, graphite and dihydrogen at \(298 \mathrm{~K} \text { are }-2220.0 \mathrm{~kJ} \mathrm{~mol}^{-1} \text {, }-393.5 \mathrm{~kJ} \mathrm{~mol}^{-1} \text { and }-285.8 \mathrm{~kJ} \mathrm{~mol}^{-1}\) respectively.
Calculate the magnitude of the enthalpy of formation of propane \(\mathrm{(C_3H_8)}\).
1. \(612\mathrm{~kJ} \mathrm{~mol}^{-1}\)
2. \(278 \mathrm{~kJ} \mathrm{~mol}^{-1}\)
3. \(104 \mathrm{~kJ} \mathrm{~mol}^{-1}\)
4. \(567 \mathrm{~kJ} \mathrm{~mol}^{-1}\)
Calculate the magnitude of the enthalpy of formation of propane \(\mathrm{(C_3H_8)}\).
1. \(612\mathrm{~kJ} \mathrm{~mol}^{-1}\)
2. \(278 \mathrm{~kJ} \mathrm{~mol}^{-1}\)
3. \(104 \mathrm{~kJ} \mathrm{~mol}^{-1}\)
4. \(567 \mathrm{~kJ} \mathrm{~mol}^{-1}\)
Subtopic: Enthalpy & Internal energy |
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For combustion of one mole of magnesium in an open container at \(\mathrm{300 ~K}\) and \(\mathrm{1 ~bar}\) pressure, \(\Delta \mathrm{cH}^{\ominus}=-601.70 \mathrm{~kJ} \mathrm{~mol}^{-1},\) the magnitude of change in internal energy for the reaction is:
[Given : \(\mathrm{R = 8.3 ~J K^{–1} mol^{–1} }\)]
1. \(\mathrm{600 ~kJ.}\)
2. \(\mathrm{400 ~kJ.}\)
3. \(\mathrm{1200 ~kJ.}\)
4. \(\mathrm{200 ~kJ.}\)
[Given : \(\mathrm{R = 8.3 ~J K^{–1} mol^{–1} }\)]
1. \(\mathrm{600 ~kJ.}\)
2. \(\mathrm{400 ~kJ.}\)
3. \(\mathrm{1200 ~kJ.}\)
4. \(\mathrm{200 ~kJ.}\)
Subtopic: Enthalpy & Internal energy |
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A gas \(\text ({ Molar~ mass } =280~ g)\) was burnt in excess \(\mathrm{O_2}\) in a constant volume calorimeter, and during combustion, the temperature of the calorimeter increased from \(298.0 \mathrm{~K} \text { to } 298.45 \mathrm{~K} \text {. }\) If the heat capacity of the calorimeter is \(2.5 \mathrm{~kJ} \mathrm{~K}^{-1}\) and the enthalpy of combustion of the gas is \(9 \mathrm{~kJ} \mathrm{~mol}^{-1}\), then the amount of gas burned is:
1. \(35 \mathrm{~g}\)
2. \(24 \mathrm{~g}\)
3. \(67 \mathrm{~g}\)
4. \(81 \mathrm{~g}\)
1. \(35 \mathrm{~g}\)
2. \(24 \mathrm{~g}\)
3. \(67 \mathrm{~g}\)
4. \(81 \mathrm{~g}\)
Subtopic: Enthalpy & Internal energy | Thermochemistry |
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