Answer: 4
Step-by-step explanation:
pH is the negative logarithm of hydrogen ion concentration in a solution. pH can be mathematically expressed as;
pH = -log(H+)
where H+ is the hydrogen ion concentration.
pH = -log(1.0 x 10-4 M)
pH = -(-4)
pH = 4 (The two minus signs cancelled out, so, the result becomes 4)
Thus, the pH of the solution is 4 (indicating an acidic solution)