Determine the molar mass (in g/mol) of the empirical formula unit for natural rubber. (Atomic weight — Polymers Chemistry Question

💡 Solution & Explanation

Natural rubber is polyisoprene. The monomer is isoprene, $C_5H_8$. Since it is an addition polymer, the empirical formula of the repeating unit remains $C_5H_8$. Molar mass = $(12 \times 5) + (1 \times 8) = 60 + 8 = 68$ g/mol.