Question

The value of delta G at 141.0 degrees celsius for the formation of phosphorous trichloride from its constituent elements,

P2(g) + 3Cl2(g) ------> 2PCl3(g)

is __________ kj/mol. At 25.0 degrees Celsius for this reaction, delta H is -720.5 kj/mol, delta G is -642.9 kj/mol, and delta S is -263.7 J/K.

A.) -829.7

B.) 1.08 x 10^5

C.) 3.65 x 10^4

D.) -683.3

E.) -611.3

Answer 1

The correct answer is option E.

Step-by-step explanation:

The Gibbs free energy is given by expression:

ΔG = ΔH - TΔS

ΔH = Enthalpy change of the reaction

T = Temperature of the reaction

ΔS = Entropy change

We have :

ΔH = -720.5 kJ/mol = -720500 J/mol (1 kJ = 1000 J)

ΔS = -263.7 J/K

T = 141.0°C = 414.15 K

`\Delta G = -720500 J/mol - (414.15 K* (-263.7 J/K))`

`= -611,288.64 J/mol = -611.28 kJ/mol\approx -611.3 kJ/mol`

The Gibb's free energy of the given reaction at 141.0°C is -611.3 kJ/mol.