Nitric oxide reacts at high temperature with hydrogen: 2NO + 2H2 → N2 + 2H2O and the following data were collected in four experiment runs. Run 1 Run 2 Run 3 Run 4
Initial conc/ mol. L-1 [H2] 0.122 0.122 0.244 0.488
Initial conc/ mol. L-1 [NO] 0.420 0.210 0.210 0.105
Initial rate/ 10-2 mol. L-1.s-1 13.5 3.39 6.77 3.39

The equation below shows a chemical reaction. a + b + heat —> c + d according to the law of conservation of energy, which statement is true? a. the reactants absorb heat because they have less energy than the products. b. the products release heat because they have more energy than the reactants. c. the reactants generate heat because they have more energy than the products. d. the products require heat to form because they have less energy than the reactants.