Posted by Steven on .
In an exothermic reaction, is the heat of the reation less than, greater than, or equal to zero?
In an endothermic reaction, is the heat of reaction less than, greater than, or equal to zero?

Chemistry 
genie_math,
Exothermic reaction  Energy is released  so it is less than zero. [Negative value]
Endothermic reaction  Energy is absorbed  greater than zero [Positive value]
Examples 
Exothermic Reactions
C(s) + O2(g) → CO2(g); ΔH = –393.5 kJ
H2(g) + 1/2 O2(g) → H2O(l); ΔH = –285.8 kJ
Endothermic Reactions
N2(g) + O2(g) → 2NO(g); ΔH = +180.5 kJ > 0
C(s) + 2S(s) → CS2(l); ΔH = +92.0 kJ > 0