The enthalpy of formation of SO2(g) is 296.7 kJ. The energy required for the decomposition of 2 mole of SO2(g) into sulphur(rhombic) and gaseous O2 is

(a) 148.35 kJ (b) 296.7 kJ (c) 593.4 kJ (d) 148.35 kJ

choose and explain

So,

S + O2 --> SO2 DeltaH = +296.7

You want Delta H for the equation:

2 SO2 --> 2S + 2 O2

Since you are flipping the equation, change it sign. Since you have 2 mol SO2, multiply the Delta H by 2 to get:

Delta H = -593.4 kJ

Now, I''m guessing that your original Delta H value should have a negative sign, so that the answer to the question would actually be +593.4 kJ.

Approve!