Aqueous iodide can be oxidized by hydrogen peroxide according to the balanced…

CHEMISTRY · Multi-part · A Level · Chemistry · Thermodynamics · Thermodynamics

Problem

Aqueous iodide can be oxidized by hydrogen peroxide according to the balanced equation

H_{2}O_{2}(aq) + 2\,I^{-}(aq) + 2\,H^{+}(aq) \rightleftharpoons I_{2}(aq) + 2\,H_{2}O(l)

298\,\text{K}

the equilibrium constant for this reaction is

K = 3.2 \times 10^{-4}

. The universal gas constant is

R = 8.314\,\text{J\,mol}^{-1}\,\text{K}^{-1}

. (a) Determine the standard Gibbs free-energy change

\Delta G^\circ

(in

\text{kJ\,mol}^{-1}

) for the reaction at

298\,\text{K}

. (b) A chemist prepares a reaction mixture in which the reaction quotient is

Q = 2.0 \times 10^{-2}

298\,\text{K}

. Calculate the Gibbs free-energy change

\Delta G

for these nonstandard conditions and state whether the mixture will spontaneously shift toward reactants or products.