question_answer 18)

  The expanded form of DDT is (a) dichlorodiphenyltrichloroethane                        (b) dichloro diethyl trichloroethane (c) dichlorodipyrydyltrichloroethane                       (d) dichloro diphenyl tetrachioroacetate

Answer:

                  (a) The expanded form of DDT is dechlorodiphenyltrichloroethane.It is an insecticide which was first synthesized in 1874. In insects it opens the sodium ion channels in neurons which leads to spas on and eventual death DDT, BHC are organic compound which were effectively used against pest during 1970 and 1980. But, now these are banned due to their less or no degradation.