4

# When liquid and vapour phases of one component system are in equilibrium (at a given temperature and pressure), the molar free energy is

More in vapour phase

More in liquid phase

Same in both the phases

Replaced by chemical potential which is more in vapour phase

C. Same in both the phases

4

# Requisites of a reversible process is that the

System and surroundings pressure be equal

Friction in the system should be absent

System and surroundings temperature be equal

None of these

4

# Air-refrigeration cycle

Is the most efficient of all refrigeration cycles

Has very low efficiency

Requires relatively large quantities of air to achieve a significant amount of refrigeration

Both (B) and (C)

4

0°C

273°C

100°C

-273°C

4

# The co-efficient of performance (COP) of a refrigerating system, which is its index of performance, is defined as the ratio of useful refrigeration to the net work. The units of __________ and COP are the same.

Kinematic viscosity

Work

Temperature

None of these

4

# When a gas is expanded from high pressure region to low pressure region; temperature change occurs. This phenomenon is related to the

Gibbs-Duhem equation

Gibbs-Helmholtz equation

Third law of thermodynamics

Joule-Thomson effect

4

0

1

2

3

4

# The total change in the enthalpy of a system is independent of the

Number of intermediate chemical reactions involved

Pressure and temperature

State of combination and aggregation in the beginning and at the end of the reaction

None of these

4

# For the gaseous phase chemical reaction, C2H4(g) + H2O(g) ↔ C2H5OH(g), the equilibrium conversion does not depend on the

Steam to ethylene ratio

Temperature

Pressure

None of these

4

# In the reaction, H2 +I2 2HI, addition of an inert gas will

Increase the partial pressure of H2

Increase the partial pressure of I2

Increase the total pressure and hence shift the equilibrium towards the right

Not affect the equilibrium conditions

4

# The expression, nCv(T2 - T1), is for the __________ of an ideal gas.

Co-efficient of thermal expansion

Compressibility

None of these

4

# High __________ is an undesirable property for a good refrigerant.

Specific heat

Latent heat of vaporisation

Viscosity

Specific vapor volume

4

# The unit of fugacity is the same as that of the

Pressure

Temperature

Volume

Molar concentration

4

# Which is an example of closed system?

Air compressor

Liquid cooling system of an automobile

Boiler

None of these

4

Isothermal

Isentropic

Isobaric

4

Isothermal

Isentropic

None of these

4

# If we increase the pressure on a substance (which is at its triple point), then the triple point

Increases

Decreases

Remains unchanged

May increase or decrease; depends on the substance

4

# The efficiency of an Otto engine compared to that of a diesel engine, for the same compression ratio will be

More

Less

Same

Data insufficient to predict

4

Isothermal

Isentropic

Polytropic

4

Zero

Positive

Negative

None of these

4

V/T = Constant

V ∝ 1/T

V ∝ 1/P

PV/T = Constant

4

# Co-efficient of Performance (COP) of a refrigerator is the ratio of the

Work required to refrigeration obtained

Refrigeration obtained to the work required

Lower to higher temperature

Higher to lower temperature

4

# The value of gas constant 'R' is

1.987 cal/gm mole °K

1.987 BTU/lb. mole °R

Both (A) and (B)

Neither (A) nor (B)

4

# The internal energy of an incompressible fluid depends upon its

Pressure

Temperature

Both (A) & (B)

Neither (A) nor (B)

4

Tds = dE + dW

dE - dW = Tds

dW - dE = Tds

Tds - dW + dE >0

4

# Which of the following is not a unit of the equilibrium constant Kp? (where, Δx = number of moles of products number of moles of reactants)

(atm)Δx, when Δx is negative

(atm)Δx, when Δx is positive

Dimensionless, when Δx = 0

(atm)Δx2, when Δx > 0

4

(T2 - T1)/T2

(T2 - T1)/T1

(T1 - T2)/T2

(T1 - T2)/T1

4

1

< 1

> 1

>> 1

4

# Partial molar free energy of an element A in solution is same as its

Chemical potential

Activity

Fugacity

Activity co-efficient

4

-94 kcal

> -94 kcal

< - 94 kcal

Zero