CAS no. (Chemical Abstracts Service Registry Number): 7782-50-5
Chlorine (dichlorine, diatomic chlorine, bertholite, sodium hypochlorite, molecular chlorine) is a greenish-yellow gas. It has a very pungent odour similar to the smell of bleach. Chlorine is mildly soluble in water, becoming hypochlorous acid and hypochloric acid.
As chlorine is heavier than air (approximately 2 ½ times), in areas with limited ventilation or air movement it will often accumulate and spread through low lying areas.
Liquid chlorine will evaporate into the air very quickly. Chlorine combines easily with all gases except for nitrogen and any of the rare gases (excluding xenon). Chlorine itself is not flammable but, being very reactive, it may explode or form explosive compounds when exposed to substances such as ammonia, hydrogen, natural gas or turpentine.
Often for shipping or storage, chlorine is cooled and pressurized turning into liquid chlorine.