The reaction X(aq) + 4Y (aq) ∏ 2Z(aq) + 3 H₂O (l) reaches equilibrium when the concentrations, at 298 K, are: [X] (aq), [Y](aq) and [Z](aq) are 1.3, 4.4 and 1.35 mmol dm^–3 respectively. Calculate the value of the equilibrium constant at this temperature.

The equilibrium constant for the oxidation of Fe²⁺ by Ag⁺

Fe²⁺ (aq) + Ag⁺ (aq)∏ Fe³⁺ (aq) + Ag (s) is 1.2 at a temperature of 764 K. What is the equilibrium constant for the reverse of this reaction?

The solubility product of barium carbonate, BaCO₃, is 2.58×10⁻⁹at a temperature of 298 K. Determine the concentration of Ba²⁺ ions in solution when a sample of barium carbonate is dissolved in water at this temperature.

Calculate the concentration of Ca²⁺(aq) ions in solution when calcium sulfate, CaSO₄(s), is added to a 0.250 mol dm^–3 solution of sulfuric acid, H₂SO₄(aq) at 298 K. The solubility product of calcium sulfate at this temperature is 4.93 ´ 10^–5.

For the reaction

½I₂(s) +  Cl₂ (l) ∏ ICl₃ (s)

the standard enthalpy and entropy of reaction are δ_rH^o = –89.5 kJ mol^–1 and δ_rS^o = -225 J K^–1 mol^–1 at 298 K. Calculate the equilibrium constant at this temperature.

The standard Gibbs energy of reaction,

SOCl₂(l) + ½ O₂(g) ∏ SO₂Cl₂(l) + ½ O₂(g) at a temperature of 298 K is –107.1 kJ mol^–1. Determine the value of the equilibrium constant at this temperature.

The equilibrium constant for the thermal decomposition of silver carbonate

Ag₂CO₃(s) ∏ Ag₂O(s) + CO₂(g) is 0.400 at a temperature of 450 K and 18.61 at 550 K. Assuming the change in the heat capacity on reaction, , determine the standard enthalpy of reaction.

The solubility product K_SP of calcium hydroxide:

Ca(OH)₂ (s) ∏ Ca²⁺ (aq) + 2OH⁻ (aq)

was studied over a range of temperatures. A plot of lnK_SP against 1/T (K⁻¹) yielded a slope of 1985 and an intercept of -19.5. Estimate the enthalpy change for this reaction.

For a reaction R ∏ P, it is observed that equilibrium the ratio of reactants to products is 4:1 at 298 K. Calculate the standard Gibbs energy change at this temperature.