Can anyone explain this question to me? Which of MgCO3, NaOH and Mg(OH)2 can be used as an indicator of halide anions in solution. I don't understand what this means.

Answer 1

I think the question is asking would you expect to see a change (usually colour change but it may not be) when you add each of the three compounds to a solution of a halide (i.e. solution containing F-, Cl-, Br-,or I- ions)

Answer 2

Thanks