# Which is the only inorganic general anesthetic in use?
a. Ether.
b. Chloroform.
c. Nitrous oxide.
d. Cyclopropane.
The correct answer is C. Nitrous oxide.
It is a colourless, odourless, heavier than air, noninflammable gas supplied under pressure in steel cylinders. It is nonirritating, but low potency anaesthetic; unconsciousness cannot be produced in all individuals without concomitant hypoxia; MAC is 105% implying that even pure N2O cannot produce adequate anaesthesia at 1 atmosphere pressure. Patients maintained on 70% N2O + 30% O2 along with muscle relaxants often recall the events during anaesthesia, but some lose awareness completely.