Which of these solutions is the most acidic? [H30+] = 4 x 10-4M
[H30+] = 6 x 10-6 M
[OH-] = 3 x 10-3M
[OH-] = 2 x 10-12 M

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.