AMMONIA 



105 



When a burning splinter is put into chlorine, it does not continue 

 to burn. Many metals, however, burn vigorously in chlorine. Thus, 

 warm copper foil takes fire, and burns to form copper chloride. If thin 

 shavings of sodium are put into chlorine, the sodium becomes covered 

 with a white deposit of common salt, and is soon used up. We thus 

 prove, both by breaking up salt, and by forming it again, that it is 

 a compound of sodium and chlorine. 



111. Hydrochloric Acid. When a jet of burning hydro- 

 gen (cf. 105) is put into a bottle of chlorine (Fig. 87), the 

 hydrogen continues to burn, and the 

 chlorine disappears. Instead of chlorine, 

 the bottle now contains hydrogen chlo- 

 ride. This is a colorless gas. It fumes, 

 or "smokes," when exposed to moist 

 air, and forms a dense fog when you 

 blow your breath over it. Hydrogen 

 chloride is very soluble in water; the 

 solution is hydrochloric acid (cf. 214). Hydrogen bums m 



A -i -i ,. , . ,. . j chlorine to give hy- 



An old name lor it is muriatic acid. drogen chloride. 



112. Ammonia. The two elements nitrogen and hy- 

 drogen form a compound called ammonia. This is a 

 colorless gas, which dissolves readily in water, forming 

 "ammonia water" or "aqua ammonice." Ammonia 

 water has the sharp odor of ammonia itself. 



Ammonia water is one of the bases (cf. 218). When 

 a bottle of "strong" ammonia water and one of "strong" 

 hydrochloric acid are brought together, the gases that 

 arise from the solutions unite to form a white cloud of 

 ammonium chloride, or "sal ammoniac" (Fig. 88). 

 This is the white solid used in making the solutions 



