An isomer of C5div2 gives total six isomeric product in chlorination . calc % yeild of the primary monochloro product which is chiral.REltivity

1 degreeC-H= 1

2 degree C-H=3

3 degree C-h=5

                      total     ==== 37.4
% yield of primary  mono chloro  pentane = no of primary hydrogens *100/37.4
                                                            = 2.6737 %
           secondary mono chloro pentane is chiral because it is have 4 different groups around the carbon

% yield of secondary mono chloro pentane  = 11.4*100/37.4
                                                               = 30%

% yield of tertiary  mono chloro pentane = 25*100/37.4
                                                         = 66.8%
as the % of the compound is more that is major product, more stable ,less reactine compound
 3. alkyl halide reacts with alkoxide to give ether it is a william son synthesis reaction