Why do you think some of the indicators used in experiment 2 were different than the ones used in experiment 1?

During selection of indicator. We choose an indicator which have pH range equivalent to the pH change of reaction to give better result and better observation.

So there are some different indicator are used in table 2 as compared to the table 1. 

- Alizarin and phenolphthalein are basic indicator and their pH range is more than 8 so they are used in table 2

- both b and d.

-since b and d are the closest coastlines then that makes it the most affected.

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