Question

Which of the following reactions represents an exothermic reaction?

Answer 1

Answer: The correct answer is $CH_4+2O_2\rightarrow CO_2+2H_2O+212,800Cal$

Explanation:

Exothermic reactions are defined as the reactions in which heat energy is released during a chemical reaction. In these reactions, energy of the products is less than the energy of the reactants. $\Delta H_{rxn}$ for these reactions are ought to be negative.

In these chemical reactions, energy term is written on the product side.

From the given chemical reactions, only one reaction satisfies the above information. The chemical reaction is:

$CH_4+2O_2\rightarrow CO_2+2H_2O+212,800Cal$

Answer 2

CH₄ + 2O₂ → CO₂ + 2H₂O + 212,800 cal
The combustion reaction of methane is an exothermic.