Question

Why is potassium not stored in kerosene oil?

Answer 1

Potassium (K) quickly undergoes reaction with air or H2O (water or moisture) and burn violently and can explode, so it must be stored in an inert medium such as an inert liquid hydrocarbon (example: kerosene) as moisture cannot enter in it.

whereas, Lithium (Li) is an extremely volatile metal and kerosene is too a volatile liquid, if stored can float on kerosene and get exposed to air which can cause explosion so it is stored in paraffin wax

Answer 2

Sodium and potassium are stored in kerosene because they are highly activate element they can easily catch fire even when in contact with air.