Classify each of the following as an exothermic or endothermic reaction:

1) 2H2 (g) + O2 (g) ⟶Δ2H2O (g) + 483.6kJ

2) 6CO2 (g) + 6H2O (l) + 15000kJ⟶C6H12O6 (aq) + 6O2 (g)

3) 2Al (s) + Fe2O3 (s) ⟶Al2O3 (s) + 2Fe (s) + 850kJ

Answer;

1) 2H2 (g) + O2 (g) ⟶Δ2H2O (g) + 483.6kJ - Exothermic

2) 6CO2 (g) + 6H2O (l) + 15000kJ⟶C6H12O6 (aq) + 6O2 (g) - Exothermic

3) 2Al (s) + Fe2O3 (s) ⟶Al2O3 (s) + 2Fe (s) + 850kJ - Exothermic

Explanation; Exothermic Reaction is a chemical reaction in which heat is given out is known as exothermic reaction, while, and endothermic Reaction is a chemical reaction in which heat energy is absorbed is known as endothermic reaction. The reaction between carbon dioxide and water is an example of an exothermic reaction. When most gases dissolve in solution, the process is exothermic meaning that heat is released as the gas dissolves The reduction of ferric oxide by aluminium is highly exothermic and therefore the iron formed will be in the molten state.