Question

If the ÄH of reaction for the following 2ZnS (s) + O 2(g) = 2ZnO (s) + 2S (s) is -290 kJ, then what is the
ÄH of reaction for the following reaction: ZnO (s) + S (s) = ZnS (s) + 1/2O 2(g)?

Would i flip the first equation? then after that i am lost

Answer 1

The question equation is just the reverse of the original equation listed except it's 1/2 of that. So you take 1/2 of the original delta H, then take the negative of the result.
The original is -290 kJ so it is just 1/2 x +290 kJ.