Chapter 2 · MCQ Read Mode

Chemical Engineering Thermodynamics

A reaction is thermodynamically spontaneous at a given temperature and pressure when:

A reaction that is exothermic and accompanied by an increase in entropy is:

The relationship between the standard Gibbs energy change and the equilibrium constant is:

In the equilibrium expression for the decomposition of calcium carbonate to calcium oxide and carbon dioxide, K equals:

The equilibrium constant of a reaction depends on:

According to the van 't Hoff equation, raising the temperature of an exothermic reversible reaction will:

Increasing the total pressure on the gas-phase reaction N2 + 3H2 giving 2NH3 will:

Adding an inert gas at constant total pressure to a gas-phase equilibrium with delta n positive will:

A catalyst added to a reversible reaction at equilibrium will:

The criterion for phase equilibrium of a species distributed between two phases is equality of its:

Absolute entropies of substances can be tabulated because:

The fact that diamond does not convert to graphite at room temperature despite a negative Gibbs energy change illustrates that:

Continuously removing a product from a reacting mixture, as in reactive distillation, allows:

For a throttling process through a valve, the property that remains constant is:

The first law of thermodynamics establishes:

For a reversible adiabatic process in an ideal gas:

The Kelvin-Planck statement of the second law asserts that no cyclic device can:

A Carnot engine operates between 600 K and 300 K. Its maximum possible efficiency is:

According to the Carnot principles, the efficiency of a reversible engine depends on:

Entropy generation in a process is:

Wet steam at a given pressure has a dryness fraction of 0.8. Its enthalpy is found from:

The isentropic efficiency of a compressor is defined as:

The work required to compress a gas is least when the compression is:

For minimum total work in a two-stage compressor with perfect intercooling, the intermediate pressure should equal:

Intercooling between the stages of an air compressor is used chiefly to:

The volumetric efficiency of a reciprocating compressor decreases when:

Maxwell relations are useful in thermodynamics because they:

A residual property is defined as the difference between the real value and the:

The Joule-Thomson coefficient of an ideal gas is:

Hydrogen and helium warm rather than cool when throttled at room temperature because:

At the critical point of a pure substance, the critical isotherm on a P-V diagram has:

The chemical potential of a species is identical to its:

The Gibbs-Duhem equation is used in practice to:

For an ideal solution, the enthalpy change on mixing is:

The fugacity coefficient of a gas approaches unity as:

Which activity coefficient model is used to predict behaviour from group contributions when no experimental data are available?

Superheating the steam entering a turbine in a Rankine cycle:

A combined cycle power plant achieves high efficiency by:

Trouton's rule states that for many liquids the ratio of the latent heat of vaporisation to the normal boiling point is about:

For a reaction of positive order, the reactor volume required for a given conversion is:

The design equation for a continuous stirred tank reactor is:

A series of equal-sized CSTRs behaves increasingly like a plug flow reactor as:

In a series reaction A giving B giving C where B is the desired product:

For two parallel reactions in which the desired product is formed by the higher-order reaction, selectivity is improved by:

The residence time distribution of a reactor is measured experimentally by:

The variance of the residence time distribution of an ideal plug flow reactor is:

Multiple steady states can occur in a CSTR carrying out an exothermic reaction because:

In a heterogeneous catalytic reaction, which sequence of steps is correct? out

Chemisorption differs from physisorption in that chemisorption:

An effectiveness factor close to unity for a catalyst pellet indicates that:

Under strong pore diffusion control, the apparent activation energy of a catalytic reaction is:

Loss of catalyst activity caused by the thermal growth of crystallites and loss of surface area is called:

For an ideal gas, the difference between the heat capacities at constant pressure and constant volume is:

The ratio of heat capacities for a diatomic ideal gas is approximately:

A mean heat capacity quoted for the range 25 to 200 degrees Celsius:

Hess's law of constant heat summation follows directly from the fact that enthalpy is:

Kirchhoff's law relates the heat of reaction at two temperatures through the:

The heat of solution of a substance must always be quoted together with:

Dissolving ammonium nitrate in water produces a marked cooling effect because the dissolution is:

Concentrated sulphuric acid should always be added to water rather than water to acid because:

The heat of mixing of two liquids forming an ideal solution is:

Pressure has only a small effect on the heat of reaction for gas-phase reactions because:

A bomb calorimeter measures the heat of combustion at constant:

If a combustion reaction produces a decrease of two moles of gas, the relationship between the enthalpy and internal energy changes is:

Kopp's rule is used to estimate the:

The coefficient of performance of a heat pump exceeds that of a refrigerator operating between the same temperatures by:

The Carnot coefficient of performance of a refrigerator operating between 250 K and 300 K is:

In the vapour compression refrigeration cycle, the expansion device is:

The pressure-enthalpy diagram is preferred for analysing refrigeration cycles because:

Subcooling the liquid refrigerant leaving the condenser:

One tonne of refrigeration is equal to:

Chlorofluorocarbon refrigerants were phased out under the Montreal Protocol because they:

Ammonia remains the preferred refrigerant in large industrial plants despite its toxicity because it has:

In an absorption refrigeration system, the component that replaces the compressor of a vapour compression system is the:

A lithium bromide-water absorption system cannot produce temperatures below 0 degrees Celsius because:

The coefficient of performance of a single-effect absorption chiller is typically about:

Adsorption refrigeration systems require two adsorbent beds because:

In the Claude liquefaction process, the improvement over the Linde process is that: