Consider the following balanced thermochemical equation for a reaction sometimes used for

H2S production:
1/8 S8 (s) + H2 (g) �¨ H2S (g) ƒ¢Hrxn = -20.2 kJ
(a)Is this an exothermic or endothermic reaction?
(b)What is ƒ¢Hrxn for the reverse reaction?
(c)What is ƒ¢H when 3.9 mol of S8 react?

I know it's exothermic
the reverse reaction is 20.2
but with part c, I am not sure: is this right?
I get 3.9 moles s8 . (-20/2kj/1/8 mol s8 = 630.24 kj

1 answer

That looks ok to me.