Question

How many of following reagent(s) is correct in options
1.$C{H}_{3}CH=CHCHO\to C{H}_{3}CH=CHCOOH:\text{Ammoniacal}AgN{O}_3$
2.$C{H}_{3}CH=CHCHO\to C{H}_{3}CH=CHC{H}_{2}OH:KMn{O}_4$
3.$R-CHO\to R-C{H}_{2}OH:NaB{H}_4$
4.$C{H}_{3}C{H}_{2}COCl\to C{H}_{3}C{H}_{2}CHO:H_2,Pd/BaS{O}_4$

Answer 1

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

(b) $KMn{O}_4$ oxidises aldehyde to carboxylic acid as it is an oxidising agent.

(c) $NaB{H}_4$ reduces aldehyde to primary alcohol.

(d) $H_2,Pd/BaS{O}_4$ reduces carbonyl chloride to aldehyde.

Hence, (1), (3) and (4) are correct.