The latent heat of vaporisation__________________?

Related Mcqs:

1. One kg of saturated steam at 100°C and 1.01325 bar is contained in a rigid walled vessel. It lias a volume of 1.673 m3. It cools to 98°C; the saturation pressure is 0.943 bar ; one kg of water vapour under these conditions has a volume of 1.789 m3. The latent heat of condensation (kJ/kg-1 ) under these conditions is___________________?

   A. 40732
   B. 2676
   C. 2263
   D. 540

2. If the vapour pressure at two temperatures of a solid phase in equilibrium with its liquid phase are known, then the latent heat of fusion can be calculated by the _________________?

   A. Maxwell’s equation
   B. Clausius-Clapeyron Equation
   C. Van Laar equation
   D. Nernst Heat Theorem

3. The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is absorbed from the hot reservoir is____________________?

   A. 100,000 kW
   B. 160,000 kW
   C. 200,000 kW
   D. 320,000 kW

4. 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_________________?

   A. Significantly less than 4.69 atm
   B. Nearly equal to 4.69 atm
   C. Significantly more than 4.69 atm
   D. Indeterminate due to lack of data

5. Heat of neutralisation of HCl and NaOH is – 57.46 kJ/Kg mole. The heat of ionisation of water will be _____________ kJ/Kg mole?

   A. 57.46
   B. -57.46
   C. 114.92
   D. -28.73

6. Heat of transition is the heat evolved or absorbed, when a substance is converted from_________________?

   A. Vapor to liquid
   B. Vapor to solid
   C. Solid to liquid
   D. One allotropic form to another allotropic form

7. A rigid vessel containing three moles of nitrogen gas at 30°C is heated to 250°C. Assume the average capacities of nitrogen to be Cp = 29.1 J/mole.°C and, Cv = 20.8 J/mole.°C. The heat required, neglecting the heat capacity of the vessel, is__________________?

   A. 13728 J
   B. 19206 J
   C. 4576 J
   D. 12712 J

8. Heat capacity of air can be approximately expressed as, Cp = 26.693 + 7.365 x10-3 T, where, Cp is in J/mole.K and T is in K. The heat given off by 1 mole of air when cooled at atmospheric pressure from 500°C to – 100°C is ____________________?

   A. 10.73 kJ
   B. 16.15 kJ
   C. 18.11 kJ
   D. 18.33 kJ

9. “The heat capacity of a solid compound is approximately equal to the sum of the heat capacities of the constituent elements.” This is the statement of___________________?

   A. Law of Petit and Dulong
   B. Kopp’s rule
   C. Nernst heat theorem
   D. Trouton’s rule

10. Absorption/evolution of heat during conversion of a substance from one allotropic form to another is termed as the heat of _____________________?

    A. Sublimation
    B. Fusion
    C. Transition
    D. Vaporisation