Given the following heats of reaction: N2 (g) + 2O2(g) à 2NO2(g) H = +67.6kJ

NO (g) + ½ O2(g) à NO2(g) H= -56.6kJ

Calculate the heat of reaction for N2(g) + O2(g) > 2NO(g)

(Give answer to 4sf)

i believe it is 40–40–20%

explanation:

more infor would

a lot

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.