Final answer:
The pH of the 10 g dm-3 HCl solution is calculated by first converting the mass concentration to molarity, which is 0.274 M for HCl. Then the pH is found to be approximately 0.56 using the formula pH = -log[H3O+].
Step-by-step explanation:
To calculate the pH of a 10 g dm-3 HCl solution, first, we need to convert the concentration from grams per decimeter cubed to molarity (moles per liter). The molar mass of HCl is approximately 36.46 g/mol. So, dividing 10 g by 36.46 g/mol gives us the molarity, which is 0.274 M.
Since HCl is a strong acid, it completely dissociates in water. Therefore, the concentration of hydronium ions [H3O+] is equal to the concentration of HCl. Using the formula pH = -log[H3O+], we find:
pH = -log(0.274) = 0.56.
The pH of the 10 g dm-3 HCl solution is approximately 0.56.