Practice Test: Question Set - 35
1. When a gas in a vessel expands, its internal energy decreases. The process involved is
- (A) Reversible
- (B) Irreversible
- (C) Isothermal
- (D) Adiabatic
2. In a P-V diagram (for an ideal gas), an isothermal curve will coincide within adiabatic curve (through a point), when
- (A) Cp < Cv
- (B) Cp = Cv
- (C) Cp > Cv
- (D) C ≥ Cv
3. The Joule-Thomson co-efficient is defined as (∂T/∂P)H. Its value at the inversion point is
- (A) ∞
- (B) 1
- (C) 0
- (D) -ve
4. The melting point of paraffin wax (which contracts on solidification) __________ with pressure rise.
- (A) Increases
- (B) Decreases
- (C) Remains unchanged
- (D) Decreases linearly
5. Enthalpy 'H' is defined as
- (A) H = E - PV
- (B) H = F - TS
- (C) H - E = PV
- (D) None of these
6. Which of the following is not an equation of state?
- (A) Bertholet equation
- (B) Clausius-Clapeyron equation
- (C) Beattie-Bridgeman equation
- (D) None of these
7. A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system
- (A) Its internal energy (U) decreases and its entropy (S)
increases
- (B) U and S both decreases
- (C) U decreases but S is
constant
- (D) U is constant but S decreases
8. What is the number of degrees of freedom for liquid water in equilibrium with a mixture of nitrogen and water vapor?
- (A) 2
- (B) 0
- (C) 3
- (D) 1
9. The chemical potential for a pure substance is __________ its partial molal free energy.
- (A) More than
- (B) Less than
- (C) Equal to
- (D) Not related to
10. A system is said to be isopiestic, if there is no __________ change.
- (A) Temperature
- (B) Pressure
- (C) Volume
- (D) None of these
11. The number of degrees of freedom at the triple point of water is
- (A) 0
- (B) 1
- (C) 2
- (D) 3
12. Maxwell's relation corresponding to the identity, dH = dS = Vdp + ∑μi dni is
- (A) (∂T/∂V)S, ni = -(∂P/∂S)V, ni
- (B) (∂S/∂P)T, ni = (∂V/∂T)P, ni
- (C) (∂S/∂V)T, ni = (∂P/∂T)V, ni
- (D) (∂T/∂P)S, ni = (∂V/∂S)P, ni
13. In a turbine, the fluid expands almost
- (A) Isothermally
- (B) Isobarically
- (C) Adiabatically
- (D) None of these
14. Critical solution temperature (or the con-solute temperature) for partially miscible liquids (e.g., phenol-water) is the minimum temperature at which
- (A) A homogeneous solution (say of phenol water) is
formed
- (B) Mutual solubility of the two liquids shows a decreasing trend
- (C) Two liquids are completely separated into two layers
- (D) None of these
15. Compressibility factor (i.e., the ratio of actual volume of gas to the volume predicted by ideal gas law) for all gases are
- (A) Always greater than one
- (B) Same at the same reduced temperature
- (C) Same at the same reduced pressure
- (D) Both (b) & (c)
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