What is the pH of a 0.018 mol L⁻¹ solution of hydrochloric acid? (A) 0.74 (B) 0.96 (C) 1.04 (D) 1.74 - HSC - SSCE Chemistry - Question 19 - 2060 - Paper 1

To calculate the pH of a hydrochloric acid (HCl) solution, we can use the formula:

$pH = -\log[H^+]$

Since HCl is a strong acid, it completely dissociates in solution. Therefore: $[H^+] = [HCl] = 0.018 \, \text{mol L}^{-1}$

Now, substituting into the pH formula:

$pH = -\log(0.018)$

Calculating:

$pH = -(-1.744) \approx 1.04$

Thus, the pH of the solution is approximately 1.04.