How many grams of HCl should be dissolved in sufficient water to get 500 ml of an aqueous solution o — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

A pH of 2.0 indicates an $[\text{H}^+]$ concentration of $10^{-2}\text{ M} = 0.01\text{ M}$. Since HCl is a strong acid, its molarity is also $0.01\text{ M}$. In 500 ml (0.5 L) of solution, the required moles of HCl = $0.01\text{ mol/L} \times 0.5\text{ L} = 0.005\text{ moles}$. The molar mass of HCl is $36.5\text{ g/mol}$. The mass required is $0.005\text{ mol} \times 36.5\text{ g/mol} = 0.1825\text{ g}$.