Question

NaCl is soluble in water, but I2 is not. Explain

Answer 1

In Sodium Chloride, the Sodium ion (Na+) and Chloride ion (Cl-) are combined by ionic forces, whereas in an Iodine Molecule, two Iodine atoms are combined by covalent bonds. Covalent bonds are always stronger than ionic bonds. So in water the weak bond (Ionic Bond) dissociates easily, and NaCl dissolves readily compared to Iodine.

Answer 2

NaCl is made up of charged ions, which can interact with the dipoles present in the water molecules.

I2 is held together by a covalant bond, neither atom is charged and they are not really attracted to water.

Answer 3

I like the answer "like dissolves like." NaCl is a polar molecule and dissolve in a polar solvent. I2 is a non-polar compound and does not dissolve in a polar solvent (at least not appreciably).