Stoichiometry

81. Assume that benzene is insoluble in water. The normal boiling points of benzene and water are 80.1 and 100°C respectively. At a pressure of 1 atm, the boiling point of a mixture of benzene and water is

1. 80.1°C
2. Less than 80.1°C
3. 100°C
4. Greater than 80.1°C but less than 100°C

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82. Assuming applicability of ideal gas law, the pure component volume of the vapor in a saturated gas can be calculated from theoretical relationship. The volumetric composition of a vapor saturated gas is independent of the

1. Nature of the liquid
2. Nature of the gas
3. Temperature of the liquid
4. Total pressure

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83. Assuming that CO₂ obeys perfect gas law, calculate the density of CO₂ (in kg/m³) at 263°C and 2 atm.

1. 1
2. 2
3. 3
4. 4

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84. At 100°C, water and methylcyclohexane both have vapour pressures of 1 atm. Also at 100°C, the latent heats of vaporisation of these compounds are 40.63 kJ/mole for water and 31.55 kJ/mole for methylcyclohexane. The vapour pressure of water at 150°C is 4.69 atm. At 150°C, the vapour pressure of methylcyclohexane would be expected to be

1. Significantly less than 4.69 atm
2. Nearly equal to 4.69 atm
3. Significantly more than 4.69 atm
4. Indeterminate due to lack of data

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85. At a constant volume, for a fixed number of moles of a gas, the pressure of the gas increases with rise of temperature due to

1. Decrease in mean free path
2. Increased collision rate among molecules
3. Increase in molecular attraction
4. Increase in average molecular speed

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86. At a temperature of 0°K, the molecules of a gas have only _________ energy.

1. Rotational
2. Vibrational
3. Translational
4. None of these

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87. At higher temperature, molal heat capacities of most of the gases (at constant pressure) _________ with increase in temperature.

1. Increases
2. Decreases
3. Remains unchanged
4. Increases linearly

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88. At higher temperatures, molal heat capacities for most of the gases (at constant pressure) _________ with increase in temperature.

1. Varies linearly
2. Increases
3. Decreases
4. Does not vary

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89. At room temperature, the product [H+] [OH-] in a solution is 10^-14 moles/litre. If, [OH-] = 10-6 moles/litre, then the pH of the solution will be

1. 6
2. 8
3. 10
4. 12

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90. At standard conditions,
N₂ + 2O₂ ⇌ 2NO₂; ΔG° = 100 kJ/mole
NO + ½O₂ ⇌ 2NO₂; ΔG° = -35 kJ/mole
The standard free energy of formation of NO in kJ/mole is

1. 15
2. 30
3. 85
4. 170

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