9. A student designed an investigation to determine which indigestion tablet was the most effective at neutralising a solution of hydrochloric acid in the school laboratory.
:Fig. 22.15
a. Describe how the student would have carried out this investigation. b. What would they have done to ensure that this was a fair test? c. The results obtained by the student are shown in the tables below:
Brand A Volume of acid neutralised (cm3 Trial 1 Trial 2 Trial 3
12 14 19
Average Brand B Volume of acid neutralised (cm3
Trial 1 Trial 2 Trial 3
16 15 15
Average Brand C Volume of acid neutralised (cm3
Trial 1 Trial 2 Trial 3
15 16 14
Average Brand D Volume of acid neutralised (cm3
Trial 1 Trial 2 Trial 3
Average i. Calculate the average volume of acid neutralised (cm3 ) for each brand.
ii. Which brand, in your opinion, is the most effective and why? iii. Which brands neutralise the same volume of acid? iv. Which results are most reliable? Justify your choice.