Calculate the pH of solutions prepared by: (d) Mixing 100.0 mL of 2.0 * 10-3 M HCl and 400.0 mL of 1.0 * 10-3 M HClO4. (Assume that volumes are additive.)

The pH scale measures the acidity or basicity of a solution, ranging from 0 to 14. A pH less than 7 indicates an acidic solution, while a pH greater than 7 indicates a basic solution. The pH is calculated using the formula pH = -log[H+], where [H+] is the concentration of hydrogen ions in the solution.

Strong acids, such as HCl and HClO4, completely dissociate in water, meaning that they release all their hydrogen ions into the solution. This complete dissociation simplifies the calculation of pH, as the concentration of the acid directly corresponds to the concentration of hydrogen ions in the solution.

When mixing solutions, the total volume and concentration of the resulting solution must be calculated based on the principle of dilution. The total moles of acid from each solution are combined, and the final concentration is determined by dividing the total moles by the total volume of the mixed solution. This is crucial for accurately calculating the resulting pH.