Equilibrium State MCQs

The existence of thermodynamic equilibrium is a core principle of thermodynamics. Thermodynamic equilibrium includes thermal equilibrium as well as other forms of equilibrium depending on the type of system. In a mechanical system at thermodynamic equilibrium, both thermal and mechanical equilibrium are achieved. Internal equilibrium indicates that no heat flows between different parts of the system, meaning all parts must be at the same temperature. In a thermally equilibrated system, all components share the same temperature. For mechanical systems, thermodynamic equilibrium also encompasses mechanical equilibrium.

A 0.1M solution of which of the substances will be basic?

(a) Sodium borate
(b) Ammonium chloride
(c) Calcium nitrate
(d) Sodium sulfate

Equimolar solutions of the following compounds are prepared separately in water. Which will have the lowest pH value?

(a) BeCl₂
(b) SrCl₂
(c) CaCl₂
(d) MgCl₂

According to Le Chatelier’s principle, adding heat to a solid and liquid in equilibrium will cause the

(a) Amount of solid to decrease
(b) Amount of liquid to decrease
(c) Temperature to rise
(d) Temperature to fall

Addition of which chemical will decrease the hydrogen ion concentration of an acetic acid solution?

(a) NH₄Cl
(b) Al₂(SO₄)₃
(c) AgNO₃
(d) NaCN

Which of the following sulfides has the largest value of Ksp?

(a) CuS
(b) CdS
(c) PbS
(d) ZnS

In some solutions, the concentration of H₃O⁺ remains constant even when small amounts of strong acid or strong base are added to them. These solutions are known as

(a) Ideal solution
(b) Colloidal solution
(c) True solution
(d) Buffer solution

At a certain temperature, 2HI ⥨ H₂ + I₂, only 50% HI is dissociated at equilibrium. The equilibrium constant is

(a) 0.25
(b) 1.0
(c) 3.0
(d) 0.6

The solubility of Fe(OH)₃ would be maximum in

(a) 0.1M NaOH
(b) 0.1M HCl
(c) 0.01M KOH
(d) 0.1M H₂SO₄

Which has the highest degree of ionization?

(a) 0.1M NH₃
(b) 0.001M NH₃
(c) 0.01M NH₃
(d) 0.0001M NH₃

All compounds are in equilibrium in a reversible reaction. If reactants are doubled in concentration, the equilibrium constant would be

(a) Reduced to half its original value
(b) Reduced to one-fourth of its original value
(c) Doubled
(d) Constant