To calculate the pH of a 0.1 M HCl solution, we can use the formula:pH = -log10[H+]Since HCl is a strong acid, it will dissociate completely in water, meaning that the concentration of H+ ions will be equal to the concentration of HCl. In this case, the concentration of H+ ions is 0.1 M.Now, we can plug this value into the formula:pH = -log10 0.1 pH = 1So, the pH of a 0.1 M HCl solution is 1.