Question

which of the following is a type of molecule that releases hydrogen ions into a solution and lowers the ph of that solution? a salt a base an acid a buffer i dont know yet

Explanation:

Acids are substances that release hydrogen ions ($H^+$) in solution. The presence of more hydrogen - ions lowers the pH of a solution. Salts are formed by the reaction of an acid and a base and do not release hydrogen ions to lower pH. Bases release hydroxide ions ($OH^-$) and raise pH. Buffers resist changes in pH.

Answer:

C. An acid