The bond energies of `C=C` and `C-C` at `298 K` are `590` and `331 kJ mol^(-1)`, respectively. The enthalpy of polymerisation per mole of ethaylene isA. `+259 kJ mol^(-1)`B. `+72 kJ mol^(-1)`C. `-259 kJ mol^(-1)`D. `-72 kJ mol^(-1)`

The bond energies of `C=C` and `C-C` at `298 K` are `590` and `331 kJ

1.	The bond energies of `C=C` and `C-C` at `298 K` are `590` and `331 kJ mol^(-1)`, respectively. The enthalpy of polymerisation per mole of ethaylene isA. `+259 kJ mol^(-1)`B. `+72 kJ mol^(-1)`C. `-259 kJ mol^(-1)`D. `-72 kJ mol^(-1)`
Answer» Correct Answer - D In the given polymerisation reaction, one mole of ethylene involves breaking of one `C=C` double bond a nd formation of three `C-C` single bonds. However, in the complete polymer chain, the number of single `C-C` bonds is two per `C=C` double bond broken. Energy required in breaking of one mole of `C=C` double bond `=590 kJ` Energy released in the formation of two moles of `C-C` single bonds `=2xx331=662 J` `:. "Net energy released per mole ethylene"` `=662-590=72 kJ` i.e., `DeltaH=-72kJ "mole"^(-1)`

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The bond energies of `C=C` and `C-C` at `298 K` are `590` and `331 kJ mol^(-1)`, respectively. The enthalpy of polymerisation per mole of ethaylene isA. `+259 kJ mol^(-1)`B. `+72 kJ mol^(-1)`C. `-259 kJ mol^(-1)`D. `-72 kJ mol^(-1)`

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