Chemistry answer check
posted by Mary on .
What quantity of heat is required to produce 5 mol of oxygen gas by this reaction? HgO(s) → Hg(l) + ½ O2(g), ΔH = +90.7kJ
I calculated 90.7*5, but my online homework says its wrong how do I calcuate this?

907.5 kJ

What do you have to multiply ½ O2 by to get 5 moles of O2?
1/2x=5
Solving for x
x=10, so you have to multiply O2 and everything else by 10 to get the following:
10HgO(s) → 10Hg(l) +5O2(g), ΔH = +907kJ not 907.5 kj. I apologize, a typo in my original response. 
907