what gas is given off by concentrated hydrochloric acid
Hydrogen chloride The compound hydrogen chloride has the chemical formula HCl and as such is a hydrogen halide. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride gas and hydrochloric acid are important in technology and industry. Hydrochloric acid, the aqueous solution of hydrogen chloride, is also commonly given the formula HCl.
Chemical weapons in World War I According to the fieldpost letter of Major Karl von Zingler, the first chlorine gas attack by German forces took place before 2 January 1915: "In other war theatres it does not go better and it has been said that our Chlorine is very effective. 140 English officers have been killed. This is a horrible weaponÂ ...".[14]