Question

2. A colourless liquid turns blue litmus paper red and reacts with magnesium to
produce a gas. What type of substance must be the colourless liquid B? How did you
identify it?​

Answer 1

Answer:

The colourless liquid must be an acid because it turns blue litmus paper red and reacts with magnesium (metal) to produce hydrogen gas, which is the property of an acid.

Answer 2

Answer:

Magnesium Oxide.

there is an activity for the same in Ncert Class 7Tb