Question

what is hydrogen cyanide and mention its chemical formula?

Answer 1

it's formula is HCN
hydrogen cyanide is a colourless , extremely poisonous and flammable liquid .. which boils at just slightly at room temperature

Answer 2

Cyanide is a fast-acting, potentially deadly chemical that can exist as both a gas and as a crystalline salt. Both forms can be lethal in high enough concentrations. Some people can detect the distinctive 'bitter almond' smell of cyanide, though this is not a reliable indicator as it doesn't always give it off, and not everyone can detect it.

 (HCN), sometimes called prussic acid