A solution of hydrochloric acid had a hydrogen ion concentration of 1.0 mol/dm3 Water was added to the hydrochloric acid until the pH increased by 1
What was the hydrogen ion concentration of the hydrochloric acid after water had
been added?

he would use the colour black

the answer is option a.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.