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Organic analysis — Question 88

Original QCE Vault practice · 7 marks

Q88 · Practice questionComplex unfamiliar7 marks

QUESTION 88 (7 marks)

A pure monoprotic carboxylic acid contains 40.0% C, 6.67% H and 53.3% O by mass. A 0.360 g sample is made up to 250.0 mL; a 25.00 mL aliquot requires 12.00 mL of 0.05000 mol L⁻¹ NaOH. The undiluted 250.0 mL acid solution has pH 3.19. Use C = 12.0, H = 1.0, O = 16.0.

a) Determine the empirical formula. [2 marks]

b) Use the titration to determine the molar mass and identify the acid. [3 marks]

c) Calculate its Ka from the concentration and measured pH. [2 marks]

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