Use the given data at 500 k to calculate δg°for the reaction
2h2s(g) + 3o2(g) → 2h2o(g) + 2so2(g)
substance h2s(g) o2(g) h2o(g) so2(g)
δh°f(kj/mol) -21 0 -242 -296.8
s°(j/k·mol) 206 205 189 248

Answer : The  value of for the reaction is -959.1 kJ

Explanation :

The given balanced chemical reaction is,

First we have to calculate the enthalpy of reaction .

where,

= enthalpy of reaction = ?

n = number of moles

= standard enthalpy of formation

Now put all the given values in this expression, we get:

conversion used : (1 kJ = 1000 J)

Now we have to calculate the entropy of reaction .

where,

= entropy of reaction = ?

n = number of moles

= standard entropy of formation

Now put all the given values in this expression, we get:

Now we have to calculate the Gibbs free energy of reaction .

As we know that,

At room temperature, the temperature is 500 K.

Therefore, the value of for the reaction is -959.1 kJ