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Acids, bases and titration — Question 41

Original QCE Vault practice · 5 marks

Q41 · Practice questionComplex familiar5 marks

QUESTION 41 (5 marks)

Methanoic acid has Ka=1.8×10−4. A student prepares a 0.020 mol L⁻¹ solution.

a) Calculate its pH using the equilibrium equation. A quadratic solution may be used. [3 marks]

b) Determine whether the approximation [HA]eq≈[HA]initial satisfies a 5% ionisation criterion. [2 marks]

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