Which statement is a correctly written thermochemical equation?

2C8H18 + 25O2 →16CO2 + 18H2O , ΔH = −5,471 kJ/mol

4Fe (s) + 3O2 (g)→2Fe2O3 (s) , ΔH = −3,926 kJ

NH4Cl → NH4+ + Cl–

C3H8 (g) + O2(g)→CO2 (g) + H2O (l) , ΔH = −2,220 kJ/mol

Reaction rate depends on how many molecules are coming into contact with each other with enough energy to react. increasing the temperature of the reactants will increase -

Nonpoint source pollution is difficult to control because it

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.