Nitric oxide can be oxidized in air to form nitrogen dioxide. at normal atmospheric concentrations this is a very slow process.
2 no(g) + o2(g) → 2 no2(g) + 232.4 kj
nitrogen dioxide is more commonly formed as a byproduct of vehicle exhaust and it contributes to acid deposition.
the equation indicates that the reaction
a. is exothermic
b. is endothermic
c. is absorbing energy
d. products have more energy than do the reactants

The combustion of methane, ch4, releases 890.4kj/mol. that is, when one mole of methane is burned,890.4 kj are given off to the surroundings. this meansthat the products have 890.4 kj less than the reactants.thus, ah for the reaction = - 890.4 kj. a negative symbolforah indicates an exothermic reaction.ch (g) + 20 (g)> co2 (g) + 2 h0 (1); ah = - 890.4 kga) how much energy is given off when 2.00 mol of ch,are burned? b) how much energy is released when 22.4g of ch. areburned?