PH scale is from 1 to 14 and indicates how acidic or basic a solution is. To find pH or pOH we need to know the H⁺ ion concentration or OH⁻ concentration. pH can be calculated using the following equation; pH = -log[H⁺] the H⁺ concentration of the given acid is 1.0 x 10⁻⁴ M. substituting this we can find the pH pH = -log[1x10⁻⁴] pH = 4 answer is 1) 4
