Question

Acetylene, c2h2, has a standard enthalpy of formation, δh° = 226.7 kj/mol, and a standard entropy change for its formation from its elements, δs° = 58.8 j/k•mol. the standard free energy of formation of acetylene is ________ kj/mol.

Answer 1

Step-by-step explanation:

The given data is as follows.

`\Delta H^(o)` = 226.7 kJ/K mol,

`\Delta S^(o)` = 58.8 J/mol =
`58.8 * 10^(-3) kJ/K mol`

T =
`25^(o)C` = (25 + 273) K = 298 K

Now, calculate the standard free energy of formation of acetylene (
`C_(2)H_(2)`) as follows.

`\Delta G^(o) = \Delta H^(o) - T \Delta S^(o)`

= 226.7 - kJ/mol - 298 K \times 58.8 \times 10^{-3} kJ/K mol[/tex]

= 209.2 kJ/mol

Thus, we can conclude that the standard free energy of formation of acetylene is 209.2 kJ/mol.

Answer 2

ΔG⁰ = ΔH⁰ - T ΔS⁰

ΔG⁰ : Standard free energy of formation of acetylene

ΔH⁰ : Standard enthalpy of formation (226.7 kJ/mol)

ΔS⁰ : Standard entropy change (58.8 J / K. mol)

T : Temperature 25°C = 298 K (room temperature)

ΔG⁰ = 226.7 - (298 x 58.8 x 10⁻³) = 209.2 kJ /mol