Question

Which substances will probably be soluble in water, a very polar solvent?

a. Sodium nitrate (NaNO₃)

b. Hexane (C₆H₁₄)

c. Isopropyl alcohol [(CH₃)₂CHOH]

b. Benzene (C₆H₆)

Answer 1

a) sodium nitrate (NaNO₃) is soluble in water as it is a salt and ionic compound.

b) Hexane (C₆H₁₄) is a hydrocarbon which is entirely composed of hydrogen and carbon and is a non-polar molecule, therefore, it is insoluble in water. Polar molecules are soluble in polar compounds while non-polar molecules are soluble in non-polar compounds.

c) Isopropyl alcohol [(CH3)2CHOH] is soluble in water as it is a polar molecule and form hydrogen bonding with water molecule which makes it soluble in water.

d) Benzene (C₆H₆) is insoluble in water as it is a hydrocarbon molecule which is nonpolar in nature. The reason for its insolubility is given in point 2.