Question

Formic acid and acetic acid are distinguished by:
A) $NaHC{O}_3$
B) $FeC{l}_3$
C) Victor Meyer Test
D) Tollen’s Reagent

Answer 1

Hint: To solve this question, we must first understand some basic concepts about Formic acid and acetic acid. Then we need to assess the concepts in such a way that we can easily tell that using whom among the given options they can be distinguished and then only we can conclude the correct answer.

Complete solution:
Before we move forward with the solution of this given question, let us first understand some basic concepts:
Formic acid: systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula $HCOOH$ . It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants.
Acetic acid: systematically named ethanoic acid, is a colourless liquid organic compound with the chemical formula $C{H}_{3}COOH$ . When undiluted, it is sometimes called glacial acetic acid. Vinegar is no less than $4\mathrm{\%}$ acetic acid by volume, making acetic acid the main component of vinegar apart from water.
Step 1: Since, formic acid $HCOOH$ differs from other carboxylic acids in having both aldehydic $(-CHO)$ and carboxylic acid group $(-COOH)$ hence Formic acid behaves as “reducing agent” and can be oxidised further into $HCOOH$ unlike other carboxylic acids.
Step 2: Since, formic acid has an aldehyde group. It reduces Tollen's reagent to silver mirror like other aldehydes. Tollen's test is not given by Carboxylic acids.
Hence in this manner we can find that among the two samples is formic acid using Tollen’s Reagent and so the other will be acetic acid.

Thus, the correct option is (D).

Note:Tollens' reagent is a chemical reagent used to determine the presence of aldehyde and aromatic aldehyde functional groups along with some alpha-hydroxy ketone which can tautomerize into aldehyde.