Question

What is the effect of dilute hydrochloric acid on phenothaline methyl orange and blue litmus paper?

Answer 1

HCl is an acid.

Phenolphthalein indicator is colorless in acidic medium and pink colored in a basic solution.

Methyl orange indicator is pink colored in acidic medium and yellow colored in basic medium.

Acid turns blue litmus paper red.

So dilute HCl solution has no effect on phenolphthalein solution as it remains colorless in acidic solution.

Methyl orange indicator would turn dilute HCl solution to reddish pink color.

Dilute HCl solution would turn blue litmus paper to red color.