Which of the gases is employed as an anaesthesia?

The gas that is commonly used as an anaesthetic is Nitrous Oxide (N2O). Nitrous oxide is a colorless, non-flammable gas with a slightly sweet taste and odor. It is also known as laughing gas due to its euphoric and pain-relieving effects. Nitrous oxide works by decreasing the sensation of pain and inducing a state of relaxation and sedation. It is commonly used in dental procedures, minor surgeries, and obstetrics. Nitrous oxide is preferred over other anaesthetic gases because it is fast-acting, has a rapid onset and offset of action, and is easily administered. It is also a relatively safe gas to use as an anaesthetic, with a low risk of side effects or complications. In summary, Nitrous Oxide is the gas that is commonly used as an anaesthetic due to its fast-acting, safe, and easily administered properties.