A chloro compound with M.F C_3H_3Cl shows the following properties (i) Decolourized bromine in C Cl_4 , (ii)Absorbed hydrogen catalytically, (iii)Gave a precipitate with ammoniacal cuprous chloride solution. Deduce the structure of the chloro compound.

A chloro compound with M.F C_3H_3Cl shows the following properties (i

1.	A chloro compound with M.F C_3H_3Cl shows the following properties (i) Decolourized bromine in C Cl_4 , (ii)Absorbed hydrogen catalytically, (iii)Gave a precipitate with ammoniacal cuprous chloride solution. Deduce the structure of the chloro compound.
Answer» Solution :(i)Since compound (A) absorbs hydrogen catalytically and decolourizes bromine in `C Cl_4`, it MUST be an unsaturated compound. (II)Since Compound (A) gives a precipitate with ammoniacal CUPROUS chloride, it must be a terminal alkyne. The only terminal alkyne with molecular FORMULA `underset"3-Chloro-1-propyne"(Cl-CH_2-C-=CH)` Step 1.To explain the reactions INVOLVED in the question (i)`underset"3-Chloro-1-propyne(A)"(Cl-CH_2-C-=CH)+ 2Br_2 overset(C Cl_4)to underset"1,1,2,2-Tetrabromo-3-chloropropane"(Cl-CH_2-CBr_2-CHBr_2)` (ii)`Cl-CH_2-C-=CH+2H_2 overset"Catalyst"to underset"1-Chloropropane"(Cl-CH_2-CH_2-CH_3)` (iii)`ClCH_2C-=CH+CuCl + NH_3 to underset"(Red ppt. )"(Cl-CH_2)-C-=C-Cu+NH_4Cl` Thus, the compound (A) is 3-chloro-1-propyne.