Question

Review energy changes by identifying the correct statements about each reaction.

Answer 1

Answer: The reaction is exothermic

The $\Delta H$ value is negative.

Heat is a product.

Explanation:

$2H_2(g)+O_2(g)\rightarrow 2H_2O(l)+136.6kcal$

Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and $\Delta H$ for the reaction comes out to be positive.

Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and $\Delta H$ for the reaction comes out to be negative.

The substances which are written on the left side of the arrow are reactants and the substances which are written on the right side of the arrow are products. Thus heat is a product.