Question

Which of the following is incorrect : -

• A. $FeC{l}_3$ is used in detection of phenol
• B. Fehling solution is used in detection of glucose
• C. Tollen reagent is used in detection of unsaturation
• D. $NaHS{O}_3$ is used in detection of carbonyl compound

Answer 1

Answer: (C)

Tollen's reagent is ammoniacal silver nitrate solution and it is used for detection of aldehyde group not for unsaturation. Aldehydes reduces Tollen's reagent to give adds and silver powder is obtained which forms silver coloured mirror in the test tube.
$R-CHO+[Ag(N{H}_3{)}_2{]}^{+}\to RCO{O}^{-}+\underset{\text{ Powder}}{\mathrm{Ag}}$