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Practical skills assessed in a written examination

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Question 10

A scientist calculated two values for the lysosomes in a specific type of white blood cell:

  • Mean volume of a lysosome: 8.0 × 10-14 cm3
  • Mean quantity of H+\text{H}^+H+ ions per lysosome: 3.2 × 10-21 mol
a.

Calculate the mean H+\text{H}^+H+ ion concentration within a lysosome in this cell. Give your answer in mol dm−3\text{mol dm}^{-3}mol dm−3.

[3]
b.

The formula to calculate pH is:

pH=−log⁡10[H+] \text{pH} = -\log_{10} [\text{H}^+] pH=−log10​[H+]

where [H+][\text{H}^+][H+] is the hydrogen ion concentration in mol dm−3\text{mol dm}^{-3}mol dm−3. Use your calculation from part (a) to find the mean pH of the lysosomes. Give your answer to 2 significant figures.

[2]

Practical skills assessed in a written examination Questions

  1. A Level
  2. /Biology
  3. /Practical skills assessed in a written examination