Question

An experimenter found that for the hydrolysis of lactose, ΔH° = +0.44 kJ mol–1 and ΔS° = +0.031 kJ mol–1 K–1. ΔG°for this reaction is:

Answer 1

Answer:

ΔG° = -8.8 kJ/mol

Explanation:

The standard Gibbs free energy of reaction (ΔG°) can be calculated using the following expression.

ΔG° = ΔH° - T.ΔS°

where,

ΔH°: standard enthalpy of reaction

T: absolute temperature

ΔS°: standard entropy of reaction

At 298 K (the temperature that is usually used), ΔG° for the hydrolysis of lactose is:

ΔG° = ΔH° - T.ΔS°

ΔG° = 0.44 kJ/mol - 298 K × 0.031 kJ/mol.K

ΔG° = -8.8 kJ/mol