Answer:
[H₃O⁺] = 0.0507 M
pH = 1.29
Step-by-step explanation:
23.1 g of HCI (a strong acid) is added to water to make 1250 mL of solution. Calculate [H₃O⁺] and pH of the solution.
Step 1: Given data
- Mass of HCl (solute): 23.1 g
- Volume of solution: 1250 mL
Step 2: Calculate the concentration of HCl
We will use the following expression.
[HCl] = mass HCl / molar mass HCl × liters of solution
[HCl] = 2.31 g / 36.46 g/mol × 1.250 L
[HCl] = 0.0507 M
Step 3: Calculate the concentration of H₃O⁺
HCl is a strong acid according to the following equation.
HCl(aq) + H₂O(l) ⇒ H₃O⁺(aq) + Cl⁻(aq)
The molar ratio of HCl to H₃O⁺ is 1:1. Then, [H₃O⁺] = 0.0507 M.
Step 4: Calculate the pH of the solution
We will use the following expression.
pH = -log [H₃O⁺]
pH = -log 0.0507
pH = 1.29