Sodium metal should be stored in

Sodium is a highly reactive alkali metal that must be stored under kerosene or mineral oil to ensure safety [1]. It reacts vigorously with oxygen and moisture in the air, generating significant heat [1]. When sodium comes into contact with water, it reacts violently to produce flammable hydrogen gas and sodium hydroxide; the heat evolved is often sufficient to cause the hydrogen to ignite. Furthermore, sodium reacts with alcohols to form sodium alkoxides and hydrogen gas [2]. It also reacts violently with mineral acids like hydrochloric acid. Because sodium does not react with hydrocarbons like kerosene, storing it submerged in this liquid prevents exposure to atmospheric moisture and oxygen, thereby preventing spontaneous combustion or hazardous chemical reactions [1].

Sources

1. [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 4: The World of Metals and Non-metals > Activity 4.6: Let us investigate (demonstration activity) > p. 52
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 4: Carbon and its Compounds > 2Na + 2CH3CH2OH → 2CH3CH2O–Na+ + H2 (Sodium ethoxide) > p. 72