UPSC 2015 CDS I GK Paper

Sodium metal should be stored in kerosene oil. It is because sodium will react violently with water and tarnish in air, forming sodium oxide, Na2O, and a small amount of Na2O2, sodium peroxide. The kerosene isolates the sodium sample from the air. It should be noted that kerosene and mineral oil are the only chemicals that make the sodium inert