For acidic solutions, which element is added to balance half-reactions?
a.
hydrogen
b.
hydroxide
c.
oxygen
d.
nitrogen

We add A Hydrogen

Explanation:

When we have a half-reaction in an acidic media usually we add (H+) hydrogen plus or protons to the reaction to balance in both sides of the reaction the amount of hydrogen.

After this step the next one is equilibrate the charges (e-) and finally we add the two half-reactions to write a short version

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.

the answer is b & c i believe : )