what happens when alkene is treated with any mineral acid
Answers
Answer:
An alkene placed in an aqueous non-nucleophilic strong acid immediately "reaches out" with its double bond and attacks one of the acid's hydrogen atoms (meanwhile, the bond between oxygen and hydrogen performs heterolytic cleavage toward the oxygen—in other words, both electrons from the oxygen/hydrogen single bond .
An addition reaction takes place.
The unsaturated double bond in the alkene becomes saturated and is replaced by a single bond, this is achieved by addition of hydrogen another group obtained from the acid.
For example, when Ethene gas is treated with concentrated sulphuric acid, the HSO4 group bonds to one carbon atom and hydrogen bonds to another and Ethyl Hydrogen Sulphate is formed.
C2H4 + H2SO4 (conc.) ----------> C2H5-HSO4
Similarly HBr and HCl react with Ethene to give Chloroethane and Bromoethane.
C2H4 + HCl -------------> C2H5Cl (Ethyl chloride)
C2H4 + HBr --------------> C2H5Br (Ethyl bromide)
These addition products on hydration with water give an alcohol(Ethanol) and the mineral acid once again.
C2H5-HSO4 + H2O -------------> C2H5OH + H2SO4