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1 markAcids, Bases, Mixtures and Household Chemicals

CSEC Integrated Science · May/June 2016 · Paper 2 · Question 3(b)(i)

Table 2 shows the pH of four brands of toothpaste (A, B, C, D) tested by Frank.

Name a substance that can be used to measure the pH of toothpaste.

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Other parts of this question

  1. 3(a)Suggest THREE habits, other than brushing regularly, that could explain why Cindy has fewer cavities than her twin Joan.[3 marks]
  2. 3(b)(ii)Arrange the four toothpaste brands in descending order of acidity (most acidic first) using their letters.[2 marks]
  3. 3(b)(iii)Identify the toothpaste brand with an incorrect pH in Table 2 and give a reason.[2 marks]
  4. 3(b)(iv)State a possible source of error that may have caused Frank to obtain the incorrect result.[1 mark]
  5. 3(b)(v)State ONE component in toothpaste that helps strengthen teeth.[1 mark]
  6. 3(c)(i)Name ONE acidic and ONE alkaline substance present in the human digestive system.[2 marks]
  7. 3(c)(ii)Name ONE digestive enzyme that operates best in an alkaline medium.[1 mark]
  8. 3(c)(iii)Explain the scientific principle by which antacids relieve digestive problems.[2 marks]

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