Why is it important to use sulfuric acid, rather than hydrochloric acid, in the formation of the diazonium salt

Which type of fossil does this image depict?

When hydrochloric acid reacts with potassium hydroxide solution, the following reaction occurs. hcl (aq) + koh (aq) h2o (l) + kcl (aq) the reaction gives off heat energy, so it is an reaction.

Explain what happens at the saturation point when adding salt to water at room temperature.