Chemical Engineering Thermodynamics MCQs

Question 1

Compound having large heat of formation is

Accepted Answer

More stable

Answer

Less stable

Answer

Not at all stable (like nascent O2)

Answer

Either more or less stable; depends on the compound

Question 2

The equation DU = Tds - PdV is applicable to infinitesimal changes occuring in

Accepted Answer

A closed system with changes in composition

Answer

An open system of constant composition

Answer

A closed system of constant composition

Answer

An open system with changes in composition

Question 3

Pick out the correct statement.

Accepted Answer

Efficiency of an Otto engine is higher than that of a diesel engine for the same compression ratio

Answer

Compression ratio of an Otto engine is comparatively higher than a diesel engine

Answer

Otto engine efficiency decreases with the rise in compression ratio, due to decrease in work produced per quantity of heat

Answer

Diesel engine normally operates at lower compression ratio than an Otto engine for an equal output of work

Question 4

With increase in temperature, the internal energy of a substance

Accepted Answer

Increases

Answer

Decreases

Answer

Remains unchanged

Answer

May increase or decrease; depends on the substance

Question 5

$$\gamma $$ = specific heat ratio of an ideal gas is equal to

Accepted Answer

All of the above

Answer

$$\frac{{{{	ext{C}}_{	ext{P}}}}}{{{{	ext{C}}_{	ext{V}}}}}$$

Answer

$$\frac{{{{	ext{C}}_{	ext{P}}}}}{{{{	ext{C}}_{	ext{P}}} - {	ext{R}}}}$$

Answer

$$1 + \frac{{	ext{R}}}{{{{	ext{C}}_{	ext{V}}}}}$$

Question 6

The standard Gibbs free energy change of a reaction depends on the equilibrium

Accepted Answer

Temperature

Answer

Pressure

Answer

Composition

Answer

All of the above

Question 7

In the ammonia synthesis reaction, N2 + 3H2 ⇋ 2NH3 + 22.4 kcal, the formation of NH3 will be favoured by

Accepted Answer

Both low temperature and high pressure

Answer

High temperature

Answer

Low pressure

Answer

Low temperature only

Question 8

A liquid under pressure greater than its vapour pressure for the temperature involved is called a __________ liquid.

Accepted Answer

Subcooled

Answer

Saturated

Answer

Non-solidifiable

Answer

None of these

Question 9

Vapour which is at a pressure smaller than the saturation pressure for the temperature involved is called a __________ vapour.

Accepted Answer

Superheated

Answer

Desuperheated

Answer

Non-condensable

Answer

None of these