Gerald's science teacher mixed room temperature samples of hydrochloric acid and sodium hydroxide in a large beaker. the solution still looked clear like water, but when the students carefully touched the beaker one at a time, it felt warm to the touch. why did the beaker most likely feel warm? a. the two liquids were not soluble in water. b. the release of a gas heated the solution. c. the energy of mixing warmed the solution. d. a chemical reaction was producing a new substance.

Option (D) is the correct answer.

Explanation:

The chemical reaction equation will be as follows.

This means a new substance has been formed and a chemical change has taken place.

A chemical reaction in which heat energy is absorbed by the reactant molecules is known as an endothermic reaction.  

For example,

On the other hand, a chemical reaction in which heat energy is released by the reactant molecules is known as an exothermic reaction.  

For example, is an exothermic reaction.

Thus, we can conclude that in the given situation the beaker most likely felt warm because a chemical reaction was producing a new substance.