Hydrogen peroxide decomposes to water and oxygen at constant pressure by the following reaction:

Question

2H2O2(l) → 2H2O(l) + O2(g) ΔH = -196 kJ

Calculate the value of q (kJ) in this exothermic reaction when 4.60 g of hydrogen peroxide decomposes at constant pressure?

Answer 1

dH is 196 kJ for 2 mol of H2O2 (i.e. 2*(2+ 32) = 68 g) so
-196 x (4.60/68) = ? kJ for 4.60 g.

Answer 2

-13.3