In an acidic solution, how does the concentration of H3O+ compare to the concentration of OH- ?

In an acidic solution i.e pH is lower than 7 has higher concentration of hydronium ions compare to the hydroxide ions.

Explanation:

Acidic solutions are those solutions which have pH value less than 7.

Alkaline solutions are those solution which has pH more than 7.

Neutral solutions are those solution which has pH value equal to 7.

The pH of the solution is defined as negative logarithm of hydronium ion concentration present in an aqueous solution .

So, in an acidic solution i.e pH is lower than 7 has higher concentration of hydronium ions compare to the hydroxide ions.

the answer to this question is 3.