A farmer in Indonesia tested soil samples from different fields. The results showed that one field had a pH of 4.5. Which substance could the farmer add to increase the pH of this soil?

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Question

A farmer in Indonesia tested soil samples from different fields. The results showed that one field had a pH of 4.5. Which substance could the farmer add to increase the pH of this soil?

Accepted Answer

calcium hydroxide — Award 1 mark for identifying a base/alkali that neutralises acid. A is incorrect — ammonium sulfate is an acidic fertiliser and would lower pH further. C is incorrect — sulfuric acid would make the soil more acidic. D is incorrect — sodium chloride is a neutral salt and would not change pH significantly.

Answer

calcium hydroxide

Answer

sodium chloride

Answer

dilute sulfuric acid

Answer

ammonium sulfate

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