Enthalpy changes over a constant pressure path are always zero for ______________ gas?

Related Mcqs:

1. Enthalpy of formation of NH3 is – 46 kJ/kg mole. The enthalpy change for the gaseous reaction, 2NH3 → N2 + 3H2, is equal to _____________ kJ/kg. mole?

   A. 46
   B. 92
   C. -23
   D. -92

2. For a constant pressure reversible process, the enthalpy change (ΔH) of the system is___________________?

   A. Cv.dT
   B. Cp.dT
   C. ∫ Cp.dT
   D. ∫ Cv.dT

3. The partial molar enthalpy of a component in an ideal binary gas mixture of composition Z, at a temperature T and pressure P, is a function only of________________?

   A. T
   B. T and P
   C. T, P and Z
   D. T and Z

4. As pressure approaches zero, the ratio of fugacity to pressure (f/P) for a gas approaches____________________?

   A. Zero
   B. Unity
   C. Infinity
   D. An indeterminate value

5. At absolute zero temperature, the _____________ of the gas is zero?

   A. Pressure
   B. Volume
   C. Mass
   D. None of these

6. Fugacity of a component in an ideal gas mixture is equal to the partial pressure of that component in the mixture. The fugacity of each component in a stable homogeneous solution at constant pressure and temperature ____________ as its mole fraction increases?

   A. Decreases
   B. Decreases exponentially
   C. Increases
   D. Remain constant

7. The compressibility factor of a gas is given by (where, V1 = actual volume of the gas V2 = gas volume predicted by ideal gas law)____________________?

   A. V1/V2
   B. V2/V1
   C. V1 – V2
   D. V1.V2

8. The density of a gas at N.T.P.is ‘ρ’. Keeping the pressure constant (i.e. 760 mm Hg), the 3 density of the gas will become ¾ 0.75 ρ at a temperature of ____________ °K?

   A. 273°
   B. 300°
   C. 400°
   D. 373°

9. 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___________________?

   A. Decrease in mean free path
   B. Increased collision rate among molecules
   C. Increase in molecular attraction
   D. Increase in average molecular speed

10. A gas at 0°C was subjected to constant pressure cooling until its volume became half the original volume. The temperature of the gas at this stage will be________________?

    A. 0°C
    B. 0°K
    C. -136.5°C
    D. -136.5°K