To calculate the pH of the solution, we first need to determine the concentration of the hydrochloric acid HCl in moles per liter M .We have 0.02 moles of HCl in 500 mL of water. To convert the volume to liters, we divide by 1000:500 mL / 1000 = 0.5 LNow, we can calculate the concentration of HCl:0.02 moles / 0.5 L = 0.04 MSince HCl is a strong acid, it will dissociate completely in water, producing an equal concentration of H+ ions:[H+] = 0.04 MNow, we can calculate the pH using the formula:pH = -log10[H+]pH = -log10 0.04 pH 1.4So, the pH of the solution is approximately 1.4.