Photo AI

A strong acid H-X dissociates in aqueous solution - AQA - A-Level Chemistry - Question 14 - 2022 - Paper 3

Question 14

A strong acid H-X dissociates in aqueous solution. H-X(aq) → 2H⁺(aq) + X⁻(aq) What is the pH of a 0.020 mol dm⁻³ solution of this acid?

Worked Solution & Example Answer:A strong acid H-X dissociates in aqueous solution - AQA - A-Level Chemistry - Question 14 - 2022 - Paper 3

Step 1

96%

114 rated

Answer

For a strong acid, it completely dissociates. Therefore, the concentration of H⁺ ions in a 0.020 mol dm⁻³ solution will be:

$[H^+] = 0.020 \, \text{mol} \, \text{dm}^{-3}$

Step 2

99%

104 rated

Answer

The pH is calculated using the formula:

$pH = -\log_{10}([H^+])$

Substituting the concentration of H⁺ ions:

$pH = -\log_{10}(0.020)$

Step 3

96%

101 rated

Answer

Using a calculator, we find:

$pH \approx 1.70$

97% of Students

Report Improved Results

98% of Students

Recommend to friends

100,000+

Students Supported

1 Million+

Questions answered

;