Question

A colourless gas which dissolves in an alkaline solution of pyrogallol

Please answer it correctly

Answer 1

Oxygen is absorbed in colorless alkaline solution of pyrogallol and turns dark brown.

Answer 2

The aquatic plant Myriophyllum spicatum produces pyrogallic acid. When in alkaline solution, it absorbs oxygen from the air, turning brown from a colourless solution. It can be used in this way to calculate the amount of oxygen in air, notably via the use of theOrsat apparatus. I hope this will help you