Question

Calculate the value of the free energy change, ΔG, for the reaction below at 750.0ºC when the pressures of POCl3 (g) = 10.00 atm, PCl3 (g) = 0.0150 atm, and O2 (g) = 0.0100 atm.

2 POCl3 (g) →2 PCl3 (g) + O2 (g)



ΔGº = 489.75 kJ

ΔHº = 542.8 kJ

ΔSº = 177.93 J/K

Answer 1

the value of the free energy change ΔG = 339.975 kJ

Step-by-step explanation:

The equation for the reaction is given as :

`2POCl_(3(g)) \ + \ 2 PCl_(3(g)) \ + \ O_(2(g))`

Equilibrium Constant K:

`K = ([PCl_3]^2[O_2])/([POCl_3]^2)\\\\K = ((0.0150)^2*(0.0100))/((10.00)^2)\\ \\K = 2.25*10^(-8)`

ΔGº = 489.75 kJ = 489750 J

T (temperature) = 750.0ºC = ( 750.0 + 273 )K

T (temperature) = 1023 K

R( rate constant) =
`8.314 \ J K^(-1) mol^(-1)`

Using the equation :

ΔG = ΔG° + RT ㏑ K

ΔG = (489750) + ( 8.314)(1023)㏑ ( 2.25 × 10⁻⁸)

ΔG = 489750 + 8505.22 × (-17.6098)

ΔG = 339974.78 J

ΔG = 339.975 kJ

Thus, the value of the free energy change ΔG = 339.975 kJ