(ii) C2H2+H2→C2H4        Ethylena,28 kg (iii) nC2H2→[−CH2−CH2−]n  n×28 kg  n×28kg polythene  or 28 kg  or 28 kg Thus 64 kg of CaC2 gives 26 kg of acetylene which in turn gives 28 kg of ethylene whose 28 kg gives 28 kg of the polymer, polythene.