Question

Who am I $ ? $
I dissolve in water, but not in kerosene.

Answer 1

Hint: We know that a polar molecule is a molecule in which one end of the molecule is positive (slightly), while the other end is negative(slightly). Hence a diatomic molecule which consists of a polar covalent bond is a polar molecule.
We also know that the molecules with high polarity are hydrophilic and mix well with other polar compounds such as water.

Complete answer:
Polar molecules have a permanent electric dipole moment. In a nonpolar substance, the attractive forces that operate between the particles are weak dispersion. Then a nonpolar substance does not dissolve in water.
In water molecules, the two positively charged hydrogens $ {H^ + } $ at one end and the negatively charged oxygen $ {O^{2 - }} $ at the other end give it two poles. Then the net charge of the water molecule is neutral. Hence water is a polar molecule.
Also, kerosene is nonpolar. Since salts ( $ NaCl $ ) are polar. Then $ NaCl $ dissolves in polar solvent and is insoluble in non-polar solvent.
Hence salts (Sodium chloride) dissolves in water and is insoluble in kerosene.

Note:
Polar molecules are the molecules that occur, when there is an electronegativity difference between the bonded atoms and it contain. Whereas nonpolar molecules are, the molecules occur when electrons are shared equally between atoms of a diatomic molecule. Nonpolar molecules contain any type of chemical bonds.