4

# Entropy of a substance remains constant during a/an __________ change.

Reversible isothermal

Irreversible isothermal

None of these

4

# Pick out the undesirable property for a good refrigerant.

High thermal conductivity

Low freezing point

Large latent heat of vaporisation

High viscosity

4

Isolated

Closed

Open

None of these

4

# For a spontaneous process, free energy

Is zero

Increases

Decreases whereas the entropy increases

And entropy both decrease

4

Solution

Formation

Dilution

Combustion

4

# During Joule-Thomson expansion of gases

Enthalpy remains constant

Entropy remains constant

Temperature remains constant

None of these

4

ds = 0

ds <0

ds > 0

ds = Constant

4

# Claude's liquefaction process employs the cooling of gases by

Expansion in an engine

Following a constant pressure cycle

Throttling

None of these

4

# __________ calorimeter is normally used for measuring the dryness fraction of steam, when it is very low.

Bucket

Throttling

Separating

A combination of separating & throttling

4

-2 RT ln 0.5

-RT ln 0.5

0.5 RT

2 RT

4

Molten sodium

Mercury

Molten potassium

4

# In reactions involving solids and liquids (where change in volume is negligible), the heat of reaction at constant pressure as compared to that at constant volume is

More

Less

Same

Unpredictable; depends on the particular reaction

4

# At triple point (for one component system), vapour pressure of solid as compared to that of liquid will be

More

Less

Same

More or less; depending on the system

4

0

< 0

< 1

> 1

4

Oxygen

Nitrogen

Air

Hydrogen

4

Non-uniformly

Isobarically

Isothermally

4

# Equilibrium constant of a reaction varies with the

Initial concentration of the reactant

Pressure

Temperature

None of these

4

# Pick out the wrong statement.

The values of (∂P/∂V)T and (∂2P/∂V2)T are zero for a real gas at its critical point

Heat transferred is equal to the change in the enthalpy of the system, for a constant pressure, non-flow, mechanically reversible process

Thermal efficiency of a Carnot engine depends upon the properties of the working fluid besides the source & sink temperatures

During a reversible adiabatic process, the entropy of a substance remains constant

4

# In case of an __________ process, the temperature of the system increases.

Isothermal compression

Isothermal expansion

4

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

Co-efficient of thermal expansion

Compressibility

None of these

4

# In an irreversible process

Tds = dE - dW = 0

dE - dW - Tds = 0

Tds - dE + dW < 0

Tds - dT + dW < 0

4

# An isolated system can exchange __________ with its surroundings.

Matter

Energy

Neither matter nor energy

Both matter and energy

4

# Gibbs-Helmholtz equation is

ΔF = ΔH + T [∂(ΔF)/∂T]P

ΔF = ΔH - TΔT

d(E - TS) T, V < 0

dP/dT = ΔHvap/T.ΔVvap

4

0

1

2

3

4

Minimum

Zero

Maximum

None of these

4

Positive

Negative

Zero

Infinity

4

# (1/V) (∂V/∂T)P is the mathematical expression

Joule-Thomson co-efficient

Specific heat at constant pressure (Cp)

co-efficient of thermal expansion

Specific heat at constant volume (CV)

4

Tds = dE + dW

dE - dW = Tds

dW - dE = Tds

Tds - dW + dE >0

4

1

0

-ve

4

# The ratio of equilibrium constants (Kp2/Kp1) at two different temperatures is given by

(R/ΔH) (1/T1 - 1/T2)

(ΔH/R) (1/T1 - 1/T2)

(ΔH/R) (1/T2 - 1/T1)

(1/R) (1/T1 - 1/T2)