4

0

1

2

3

D. 3

4

# Internal energy change of a system over one complete cycle in a cyclic process is

Zero

+ve

-ve

Dependent on the path

4

# Out of the following refrigeration cycles, which one has the minimum COP (Co-efficient of performance)?

Air cycle

Carnot cycle

Ordinary vapour compression cycle

Vapour compression with a reversible expansion engine

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

# 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

# For a given substance at a specified temperature, activity is __________ to fugacity.

Directly proportional

Inversely proportional

Equal

None of these

4

(dF)T, p < 0

(dF)T, p > 0

(dF)T, p = 0

(dA)T, v < 0

4

# In a homogeneous solution, the activity coefficient of a component depends upon the

Pressure

Composition

Temperature

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

4

Carnot

Air

Absorption

vapour-ejection

4

Zero

Negative

More than zero

Indeterminate

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

# 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

6738.9

6753.5

7058.3

9000

4

Molten sodium

Mercury

Molten potassium

4

# What is the value of maximum COP in case of absorption refrigeration, if refrigeration provided is at temperature, TR (where, T1 and T2 are source & surrounding temperatures respectively.)?

TR/(T2 - TR) × (T1 - T2)/T1

TR/(T2 - TR) × T1/(T1 - T2)

TR/(T1 - TR) × (T1 - T2)/T1

None of these

4

R loge 4

R log10 4

Cv log10 4

Cv loge 4

4

# Which of the following will increase the volume of a real gas by four times?

Doubling the absolute temperature as well as pressure of the gas

Reducing pressure to one fourth at constant temperature

Reducing temperature to one fourth at constant pressure

Reducing the temperature to half and doubling the pressure

4

Solution

Formation

Dilution

Combustion

4

# For an exothermic reaction

Only enthalpy change (ΔH) is negative

Only internal energy change (ΔE) is negative

Both ΔH and ΔE are negative

Enthalpy change is zero

4

Pressure

Solubility

Temperature

None of these

4

# Which one is true for a throttling process?

A gas may have more than one inversion temperatures

The inversion temperature is different for different gases

The inversion temperature is same for all gases

The inversion temperature is the temperature at which Joule-Thomson co-efficient is infinity

4

# If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as

Solubility increases as temperature increases

Solubility increases as temperature decreases

Solubility is independent of temperature

Solubility increases or decreases with temperature depending on the Gibbs free energy change of solution

4

0

< 0

> 0

4

# An irreversible process

Is the analog of linear frictionless motion in machines

Is an idealised visualisation of behaviour of a system

Yields the maximum amount of work

Yields an amount of work less than that of a reversible process

4

Oxygen

Nitrogen

Air

Hydrogen

4

# __________ increases with increase in pressure.

The melting point of wax

The boiling point of a liquid

Both (A) and (B)

Neither (A) nor (B)

4

0

1

2

3

4

-273

0

-78

5

4

Momentum

Mass

Energy

None of these

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)