Determine whether the following are endothermic or exothermic.
2H2O2 (l) �¨ 2H2O(l) + O2(g)
∆H = -190 kj
C(s) + H2O (g) �¨ CO (g) + H2 (g)
∆H = +113 kj
C4H9OH(l) + 6 O2(g) �¨ 4 CO2(g) + 5 H 2O(g)
∆H = -2456.1
2 C(s) + H2(g) �¨ C2H2(g)
∆H = +226.71
N2O5(s) + H2O(l) �¨ 2 HNO3(aq)
∆H = -86.0
thanks!
1 answer
The endothermic reactions have negative ∆H values, because, for thosue reactions, chemical energy is lost when heats of formation of reactants and products are compared at the same temperature.