Unsymmetric example sentences

Addition in unsymmetrical alkynes takes place according to Markovnikov rule.Let us illustrate this by taking addition of HBr to symmetrical and unsymmetrical alkenes.In the presence of peroxide, addition of HBr to unsymmetrical alkenes like propene takes place contrary to the Markovnikov rule.Let us illustrate this by taking addition of HBr to symmetrical and unsymmetrical alkenesHydrogen halides (HCl, HBr,HI) add up to alkenes to form alkyl halides.