[ajax0604]

I've read that 1,1-dichloroethane can be made by reacting chloroethane with HCl but 1,2-dichloroethane is made by reacting ethene with chlorine gas. Could someone explain why different methods are used to make the two molecules? Could free radical substitution of ethane with chlorine produce both molecules but it's not the preferred method? 

[Hunter2]

Many ways guide to Rome. You can made 1.1-product  by using vinyl-chloride and HCl. Markovnikov addition. 1.2 -product by using ethene and chlorine.