Question

(x) Calculate the work done during the reaction represented by
the following thermochemical equation at 300 K:
CH4 +202 → CO2 + 2H2O
(g) (g) (g) (1)
(R=8-314 JK-'mol-!)
(a) +4.988 kJ
(b). - 4.988 kJ
(c) - 49.88 kJ
(d) + 49.88 kJ​

Answer 1

Given: Thermochemical equation CH4 (g) +202 (g)  → CO2 (g) + 2H2O (l)

To find: Work done during the rection.

Solution:

• As we have given the thermochemical equation, so we can identify that the equation is already balanced. So no need to balance again.
• Now, we know the formula of Δn which is:

                Δn = no. of gaseous product - number of gaseous reactant

                      = 1 - (1+2)

                      = -2

• Now putting all the values in the formula of work done, we get:

                  W = ΔnRT

                      = -2 ( 8.314) (300)

                      = 4988.4 J

                  W = 4.9884 KJ

Answer:

               The work done during the reaction is 4.9884 KJ