Question

The standard Gibbs energy of formation (Δ_fG°) is the"

A) Heat required to form one mole of a substance from its elements
B) Heat released when one mole of a substance reacts with another
C) Gibbs energy change during a reaction at standard conditions
D) Total Gibbs energy change of a substance in all forms

Answer 1

The standard Gibbs energy of formation (ΔfG°) is the energy change when 1 mole of a substance is formed from its elements in their standard states, and it's zero for any element in its standard state. It's used in calculating the standard Gibbs energy change (ΔG°) for a reaction.

Step-by-step explanation:

The standard Gibbs energy of formation (ΔfG°) is the Gibbs energy change that occurs when 1 mole of a substance is formed from its elements in their standard states. By definition, for any element in its standard state, such as O2(g) at 298.15 K and 1 atm pressure, ΔfG° is zero. To calculate the standard Gibbs energy change (ΔG°) for a reaction, we use the formula ΔG° = ΣΔG°f (products) - ΣΔG°f (reactants), where Σ represents the sum over all substances.