4

Isothermal

Isobaric

Polytropic

A. Isothermal

4

# Which of the following represents the Virial equation of state?

T = [RT/(V- b)] - [a/√T. V(V + b)]

PV/RT = 1 + (B/V) + (C/V2) + ……

n1u2 + μ2μ1 = 0

None of these

4

# Which of the following equations is used for the prediction of activity co-efficient from experiments?

Van Laar equation

Margules equation

Wilson's equation

All (A), (B) and (C)

4

Positive

Negative

Zero

Infinity

4

# High pressure steam is expanded adiabatically and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process:

Δ H = 0 and ΔS = 0

Δ H ≠ 0 and ΔS = 0

Δ H ≠ 0 and ΔS ≠ 0

Δ H = 0 and ΔS ≠ 0

4

# Adiabatic compression of a saturated water vapour makes it

Supersaturated

Superheated

Both (A) and (B)

Neither (A) nor (B)

4

# In an ideal solution, the activity of a component equals its

Mole fraction

Fugacity at the same temperature and pressure

Partial pressure

None of these

4

# The chemical potential of a component (μi) of a phase is the amount by which its capacity for doing all work, barring work of expansion is increased per unit amount of substance added for an infinitesimal addition at constant temperature and pressure. It is given by

(∂E/∂ni)S, v, nj

(∂G/∂ni)T, P, nj = (∂A/∂ni) T, v, nj

(∂H/∂ni)S, P, nj

All (A), (B) and (C)

4

# The melting point of paraffin wax (which contracts on solidification) __________ with pressure rise.

Increases

Decreases

Remains unchanged

Decreases linearly

4

# The work done in isothermal compression compared to that in adiabatic compression will be

Less

More

Same

More or less depending upon the extent of work done

4

(dF)T, p < 0

(dF)T, p > 0

(dF)T, p = 0

(dA)T, v < 0

4

# Pick out the correct statement:

In an isothermal system, irreversible work is more than reversible work

Under reversible conditions, the adiabatic work is less than isothermal work

Heat, work, enthalpy and entropy are all 'state functions'

Matter and energy cannot be exchanged with the surroundings in a closed system

4

Saturated vapour

Solid

Gas

Liquid

4

# The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is

Less pronounced

More pronounced

Equal

Data insufficient, can't be predicted

4

# Melting of ice exemplifies a/an

Endothermic reaction

Exothermic reaction

Process involving a chemical reaction

4

# In case of vapour compression refrigeration system, elevating the evaporator temperature (keeping the condenser temperature constant) results in

Enhanced COP

Decreased COP

No change in the value of COP

Increased or decreased COP; depending upon the type of refrigerant

4

# PVy = constant, holds good for an isentropic process, which is

Reversible and isothermal

Isothermal and irreversible

4

# Pick out the wrong statement

Phase rule variables are intensive properties

Heat and work are both state function

The work done by expansion of a gas in vacuum is zero

CP and CV are state function

4

Heat pump

Heat engine

Carnot engine

None of these

4

# Which of the following is an extensive property of a system?

Heat capacity

Molal heat capacity

Pressure

Concentration

4

# (∂T/∂P)H is the mathematical expression for

Specific heat at constant pressure (Cp)

Specific heat at constant volume (Cv)

Joule-Thompson co-efficient

None of these

4

# An isolated system can exchange __________ with its surroundings.

Matter

Energy

Neither matter nor energy

Both matter and energy

4

349

651

667

1000

4

# What happens in a reversible adiabatic compression?

Heating occurs

Cooling occurs

Pressure is constant

Temperature is constant

4

Mass

Energy

Momentum

None of these

4

2HI H2 + I2

N2O4 2NO2

2SO2 + O2 2SO3

None of these

4

0

+ve

-ve

4

Temperature

Specific heat

Volume

Pressure

4

# The compressibility factor for an ideal gas is 1. Its value for any other real gas is

1

< 1

> 1

Either (B) or (C), depends on the nature of the gas

4

# At a given temperature, the volume of a gas dissolved in a solvent __________ with increase in pressure.

Increases

Decreases

Remains unchanged

May increase or decrease; depends on the gas