In chemical analysis, the presence of a methyl ketonic group is tested with I_(2) in presence of an alkali like NaOH or KOH. In another chemical analysis, aldehyde group is tested either by Tollens' reagent (AgNO_(3)NH_(3)OH) which gives silver mirror or by Fehling's solution (CuSO_(4)+NaOH+ Roschelle salt) which gives red ppt. of copper (I) oxide. Q. Consider the following compounds: I. CH_(3)-overset(O)overset(||)(C)-CH_(2)-overset(O)overset(||)(C)-CH_(3) II. CH_(3)-overset(O)overset(||)(C)-overset(O)overset(||)(C)-CH_(3) III. CH_(3)-overset(O)overset(||)(C)-OH IV. CH_(3)-overset(O)overset(||)(C)-Cl Which will give iodoform test?

In chemical analysis, the presence of a methyl ketonic group is tested

1.	In chemical analysis, the presence of a methyl ketonic group is tested with I_(2) in presence of an alkali like NaOH or KOH. In another chemical analysis, aldehyde group is tested either by Tollens' reagent (AgNO_(3)NH_(3)OH) which gives silver mirror or by Fehling's solution (CuSO_(4)+NaOH+ Roschelle salt) which gives red ppt. of copper (I) oxide. Q. Consider the following compounds: I. CH_(3)-overset(O)overset(\|\|)(C)-CH_(2)-overset(O)overset(\|\|)(C)-CH_(3) II. CH_(3)-overset(O)overset(\|\|)(C)-overset(O)overset(\|\|)(C)-CH_(3) III. CH_(3)-overset(O)overset(\|\|)(C)-OH IV. CH_(3)-overset(O)overset(\|\|)(C)-Cl Which will give iodoform test?
Answer» Only I Both I and II Only II All Solution :ALTHOUGH `CH_93)COCH_(2)COCH_(3)` contains a `CH_(3)CO-` group linked to carbon, YET it does not undergo iodoform test. The reason being that the iodination OCCURS at the more reactive `CH_(2)` group rather than at the terminal `CH_(3)` which is essential for iodoform test to occurs. Only `CH_(3)CO-COCH_(3)` gives iodoform test.