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2 marksRates of Reaction

CSEC Chemistry · January 2008 · Paper 2 · Question 1(a)(iii)

A student investigates reaction rates using five KIO3 solutions of different concentrations (0.001 to 0.005 mol dm⁻³) and a fixed volume of Solution P (containing NaHSO3, dilute H2SO4, and starch indicator). The time for a blue color to appear is recorded using stopwatches, as shown in Figure 1.

Explain the shape of the graph.

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Other parts of this question

  1. 1(a)(i)Complete Table 1 below to show, for the concentration of KIO3 solution used, the corresponding times in seconds (s) and the reciprocal times (1/t) at which the…[7 marks]
  2. 1(a)(ii)Using the graph paper on page 5, plot the reciprocal of time against the concentration of KIO3.[5 marks]
  3. 1(b)Complete Table 2 below for tests carried out on the mixture labelled as Q.[3 marks]
  4. 1(c)(i)Apparatus and materials needed[2 marks]
  5. 1(c)(ii)Description of the method to be used[2 marks]
  6. 1(c)(iii)ONE variable needed to be controlled[1 mark]
  7. 1(c)(iv)ONE precaution to be taken[1 mark]
  8. 1(c)(v)Expected results[2 marks]

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