Question

Tollen's reagent used for the distinction of aldehydes with ketones is

• A. $aq.CuS{O}_4$
• B. $\left[Ag\right(N{H}_3{)}_2{]}^{+}$
• C. $Cu(\text{Citrate}{)}_2^{2-}$
• D. None of the above

Answer 1

The correct option is B $\left[Ag\right(N{H}_3{)}_2{]}^{+}$

Tollen's reagent refers to the chemical reagent which is used in the detection of an aldehyde functional group, an aromatic aldehyde functional group, or an alpha hydroxy ketone functional group in a given test substance.
Ketones don't give silver mirror with Tollens' reagent.
Tollen's reagent is ammoniacal solution of silver nitrate
A positive test gives precipitate of elements silver.$RCHO+2\left[Ag\right(N{H}_3{)}_2{]}^{+}+3O{H}^{-}\to RCO{O}^{-}+2Ag\downarrow +2H_{2}O+4N{H}_3\text{Aldehyde}\text{Tollen's Reagent}\text{Carboxylate ion}\text{Silver mirror}$