Question

For the reaction \[\ce{2NO2 (g) ⇌ N2O4(g)}\], when ΔS = −176.0 JK⁻¹ and ΔH = −57.8 kj mol⁻¹, the magnitude of ΔG at 298 K for the reaction is ______ kJ mol⁻¹. (Nearest integer)

Options

• 2

• −5

• 8

• 10

Answer 1

For the reaction \[\ce{2NO2 (g) ⇌ N2O4(g)}\], when ΔS = −176.0 JK⁻¹ and ΔH = −57.8 kj mol⁻¹, the magnitude of ΔG at 298 K for the reaction is −5 kJ mol⁻¹. (Nearest integer)

Explanation:

ΔG = ΔH − ΔS

Standardize Units:

ΔS must be in kJ to match ΔH.

−176.0 J/K

= −0.176 kJ/K

Plug in the Values:

ΔG = −57.8 − (298× −0.176)

ΔG = −57.8 − (−52.448)

ΔG = −G = -57.8 + 52.448

ΔG = −5.352 kJ mol⁻¹

The calculated value is −5.352. When rounding to the nearest integer, we get −5.