A cotton swab is dipped into concentrated hydrochloric acid (producing hydrogen chloride gas) while a second on is dipped into concentrated aqueous ammonia (producing ammonia gas). Both cotton swabs ...

Method: Dip a glass rod in concentrated hydrochloric acid and put this in a sample of the gas. Result: If ammonia is present, a white ‘smoke’ of ammonium chloride is observed.

It's pretty common for things to react as liquids and solids, but they can also react as gases. To show this I just need some ...

Guano contains water, ammonia, ulmic, uric ... consisting of the carbonates and phosphates separable by hydrochloric acid from the residue aforesaid ; also sand which is insoluble.