Q11(a). Calcium in powdered milk
Calcium in powdered milk is determined by ashing a 1.50 g sample and then titrating calcium with EDTA solution, 12.1 mL being required. EDTA was standardized by titrating 10.0 mL of a zinc solution prepared by dissolving 0.632 g zinc metal in acid and diluting to 1 L (10.8 mL EDTA is required for titration). What is the concentration of calcium in the powdered milk in parts per million?
Answer in brief
Calcium content = 2.89 × 10³ ppm by mass (2.89 mg g⁻¹), assuming the titre represents the whole 1.50 g sample.
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CoversEDTA titrationcalcium determinationppm calculationstandardisation of EDTAcomplexometric titration
All parts of Question 11
- 11(a) Calcium in powdered milk10 marks
- 11(b) High oxidation states in the first d series10 marks
- 11(c)(i) Why HfO₂ is denser than ZrO₂5 marks
- 11(c)(ii) Coordination numbers of first-row metals5 marks