Question

For the following, identify the process as a spontaneous process, a nonspontaneous process, or an equilibrium process at the specified temperature: (Assume that the thermodynamic data in the appendix do not vary with temperature.) CO2(g) → CO2(aq) at 25°C

Answer 1

A nonspontaneous process

Step-by-step explanation:

The spontaneity of a reaction is given by the standard Gibbs free energy (ΔG°). We can calculate ΔG° using the following expression.

ΔG° = ∑np . ΔG°f(p) - ∑nr . ΔG°f(r)

where,

ni are the moles of reactants and products

ΔG°f(p) are the standard Gibbs free energies of formation of reactants and products

For the equation,

CO₂(g) → CO₂(aq)

ΔG° = 1 mol × ΔG°f(CO₂(aq)) - 1 mol × ΔG°f(CO₂(g))

ΔG° = 1 mol × (-386.0 kJ/mol) - 1 mol × (-394.4 kJ/mol)

ΔG° = 8.4 kJ

By convention, ΔG° > 0 means that the reaction is nonspontaneous.