Question

Which metal is stored in kerosene oil?
A. Sodium
B. Calcium
C. Iron
D. None of the above

Answer 1

Hint: To answer this question we must first understand why some metals are stored in kerosene. Some highly active metals are stored in kerosene so that they do not come in contact with light or moisture and undergo certain explosive reactions.

Complete step by step answer:
1. From the reactivity series of metals, we know that Sodium and Potassium are the most reactive metals and hence are present at the top.
2. We should remember that Sodium belongs to the third group of the modern periodic table, which means that a sodium atom has 3 shells.
3. Its electronic configuration suggests that it has 2 electrons in the first shell, 8 in the second and 1 in the last shell.
4. Thus, to gain stability it can either complete its octet in the outermost shell by gaining 7 more electrons or can lose an electron from its valence shell.
5. Since, it is easier for the sodium atom to lose one electron. This tendency to easily lose the single electron in its outermost shell makes it a highly reactive substance.
6. It reacts as soon as it comes in contact with air or moisture and catches fire and so it is kept immersed in kerosene.

Hence, the correct answer is Option (A).

Note: You must be wondering why we choose kerosene among all the substances available to us. This is simply because kerosene is a hydrocarbon that is extremely hydrophobic hence it does not let the metal come in contact with moisture or air.