When copper sulfate is dissolved in pure water ... used to give an approximate pH value for a solution by comparing the colour of the indicator to the colour chart below. An indicator is a ...

This is a displacement reaction. Two new products have formed: copper and iron sulfate. In fact, we can see the colour of the solution changes as the copper sulfate gets replaced by iron sulfate.

Dr MH Usmani, a dermatologist at Balrampur Hospital, emphasised the importance of a patch test before using any colour ...