Final answer:
a) The pH of a 9.62 × 10⁻² M HClO₄ solution is 1.15.
b) The pH of a solution that is 4.7 × 10⁻² M in HClO₄ and 4.8 × 10⁻² M in HCl is 1.02.
c) The pH of a solution that is 1.10% HCl by mass is 3.52.
Step-by-step explanation:
a) To determine the pH of a solution, you can use the equation: pH = -log[H+]. In this case, the hydronium ion concentration of HClO₄ is 9.62 × 10⁻² M, so the pH can be calculated as follows:
pH = -log(9.62 × 10⁻²) = 1.15.
b) To determine the pH of a solution that contains both HClO₄ and HCl, you need to consider the combined hydronium ion concentration. The total concentration of H+ ions can be calculated as
4.7 × 10⁻² + 4.8 × 10⁻² = 9.5 × 10⁻² M.
Thus, the pH can be calculated as follows:
pH = -log(9.5 × 10⁻²) = 1.02.
c) To determine the pH of a solution that is 1.10% HCl by mass, you first need to convert the mass of HCl to moles. Assuming the total mass of the solution is 100 g, the mass of HCl would be 1.10 g (1.10% of 100 g). The moles of HCl can be calculated using its molar mass
(36.46 g/mol): 1.10 g / 36.46 g/mol = 0.0302 mol
The volume of the solution can be calculated using the density of 1.01 g/mL:
100 g / 1.01 g/mL = 99.01 mL
Finally, the Molarity of HCl can be calculated using the moles and volume:
Molarity = 0.0302 mol / 99.01 mL = 0.000305 M
The pH can then be calculated as follows:
pH = -log(0.000305) = 3.52.