Give chemical tests to distinguish between compounds inthe following pairsof substances ,(i) Ethanal and Propanal (ii) Benzoic acid and Ethyl benzoate(b)An origanic compound contains 69.77%carbon , 11.63%hydrogen and rest oxygen . the molecular mass of the compound is 86. It doesnot reduce tollen 's reagent but forms an addition compound with sodium hydrogen sulphite and gives positive iodoform test. On vigorous oxidation it ethanoic and propanoic acids . Derive the structure of the compound.

Give chemical tests to distinguish between compounds inthe following p

1.	Give chemical tests to distinguish between compounds inthe following pairsof substances ,(i) Ethanal and Propanal (ii) Benzoic acid and Ethyl benzoate(b)An origanic compound contains 69.77%carbon , 11.63%hydrogen and rest oxygen . the molecular mass of the compound is 86. It doesnot reduce tollen 's reagent but forms an addition compound with sodium hydrogen sulphite and gives positive iodoform test. On vigorous oxidation it ethanoic and propanoic acids . Derive the structure of the compound.
Answer» Solution :(a) (i)Distinction between Ethanaland Propanal : Ethanal`(CH_(3)CHO)` and propanal `(CH_(3)CH_(2)CHO)` can be DISTINGUISHED by the iodoform test . Ethanal reacts with `I_(2)//NAOH(orNaOI)`to give yellow ppt . Ofiodoform but propanal does not REACT with `I_(2)//NaOH`. `UNDERSET("Ethanal")(CH_(3)CHO+3I_(2))+4NaOHoverset(Delta)toHCOONa+underset(("Yellow ppt."))(CHI_(3))+3NOI+3H_(2)O` `underset("Propanal")(CH_(3)CH_(2)CHO)overset(I_(2)//NaOH)to` No Yellow ppt. of `CHI_(3)` (ii)Benzoic acid and Ethyl benzoate :These compounds can be distinguished by using`NaHCO_(3)` test . Benzoic acid produces brisk effervescene with `NaHCO_(3)`solution while ethyl benzoate does not . `underset("Benzoic acid")(C_(6)H_(5)COOH)+NaHCO_(3)tounderset("Sod . benzoate")(C_(6)H_(5)COONa+CO_(2)+H_(2)O)` `C_(6)H_(5)COOC_(2)H_(5)overset(NaHCO_(3)"Soln.")to` No effervescence due to evolution of `CO_(2)` GAS.