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2 marksUncertainty in Measurements

CAPE Chemistry Unit 2 · May/June 2026 · Paper 2 · Question 2(a)(ii)

This module covers analytical methods and separation techniques. A student performed a titration and deduced the following titre volumes (in mL): 14.11, 13.99, 14.32, 14.21.

Calculate the standard deviation in the mean volume given. S = √(Σ(x-x̄)² / (n-1))

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Other parts of this question

  1. 2(a)(i)Calculate the mean volume.[2 marks]
  2. 2(a)(iii)Outline the FIVE steps to be taken to determine the accuracy and uncertainty in dispensing 15.0 mL of water from a burette.[5 marks]
  3. 2(a)(iv)Given the volumes delivered from A, B and C, state which glassware should give EACH of the following. The most accurate volume. The least accurate volume.[2 marks]
  4. 2(b)Use the information above to determine the chemical formula of the hydrate of CuSO4, that is, the x in CuSO4•xH2O.[4 marks]
  5. 2(c)(i)Write the equation for the reaction between the sulfate of a Group 1 element (M) and barium chloride.[2 marks]
  6. 2(c)(ii)calculate the mass of sulfate in the Group 1 sulfate. determine the % weight of sulfate in the Group 1 sulfate.[5 marks]
  7. 2(d)Give TWO examples in which gravimetric analysis (by precipitation) can be employed in quality control. Indicate the product(s) obtained as the precipitate.[4 marks]
  8. 2(e)List the FOUR main steps involved in mass spectrometry.[4 marks]

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