Question

What is the pH of a solution in which 222 mL of HCl(g), measured at 26.0 ∘C and 1.06 atm, is dissolved in water to give 1.5 L of aqueous solution? (Hint: Use the ideal gas law to find moles of HCl first.)

Answer 1

Answer:

6.39 × 10⁻³ M

Explanation:

First, we will calculate the moles of HCl using the ideal gas equation.

P × V = n × R × T

n = P × V / R × T

n = 1.06 atm × 0.222 L / 0.0821 atm.L/mol.K × (26.0 + 273.15) K

n = 9.58 × 10⁻³ mol

The molar concentration of HCl is:

M = moles of HCl / liters of solution

M = 9.58 × 10⁻³ mol / 1.5 L

M = 6.39 × 10⁻³ M