Question

The unsaturated hydrocarbon butadiene (C4H6) dimerizes to 4-vinylcyclohexene (C8H12). When data collected in studies of the kinetics of this reaction were plotted against reaction time, plots of [C4H6] or ln[C4H6] produced curved lines, but the plot of 1/[C4H6] was linear.

a) What is the rate law for the reaction?

Answer 1

The dimerization of butadiene to 4-vinylcyclohexene folows second order kinetics and its rate law will be given by :

`R=k[C_4H_6]^2`

Step-by-step explanation:

`2C_4H_6\rightarrow C_8H_(12)`

The rate of the reaction ;

`R=k[C_4H_6]^x`

As given in the question , that graph of time verses
`(1)/([C_4H_6])` was linear but plots of
`[C_4H_6]` or
`\ln[C_4H_6]` was curved.

Generally:

Graph of time verses
`[concentration]` for zero order reaction is linear with negative slope.

Graph of time verses
`\ln [concentration]` for secon order reaction is linear with negative slope.

Graph of time verses
`(1)/([concentration])` for secon order reaction is linear with positive slope.

So, the dimerization of butadiene to 4-vinylcyclohexene folows second order kinetics and its rate law will be given by :

`R=k[C_4H_6]^2`