Question

Methylamine in water reacts with ferric chloride to precipitate hydrated ferric oxide.
(a)- True
(b)- False

Answer 1

When methyl amine reacts with water, it makes the water split into hydrogen ions and hydroxyl ions. The hydroxyl ion when reacting with ferric chloride forms $F{{e}_{2}}{{O}_{3}}.3{{H}_{2}}O$.

Complete step by step answer:
Ferric chloride is a compound that when reacted with hydroxide ion, the chloride ions releases and precipitates ferric oxide. The formula of ferric oxide is $F{{e}_{2}}{{O}_{3}}.3{{H}_{2}}O$.
So, if the precipitate $F{{e}_{2}}{{O}_{3}}.3{{H}_{2}}O$has to be formed then the solution must contain hydroxyl ions. This method is also used for checking the presence of hydroxyl ions in the solution. The color of hydrated ferric oxide is reddish-brown.
Methylamine is an organic compound in which the methyl group is attached to a primary amine. The formula of methylamine is $C{{H}_{3}}-N{{H}_{2}}$.
So, when methylamine is reacted with water, +I-effect takes place. Now, due to this +I-effect, the amine group becomes more basic than water. Now, because of this basic character it forms methylammonium ions and releases hydroxyl ions in the water. The reaction is given below:
$C{{H}_{3}}-N{{H}_{2}}+{{H}_{2}}O\to C{{H}_{3}}-NH_{3}^{+}+O{{H}^{-}}$
Now when this solution is treated with ferric chloride, it forms a precipitate of hydrated ferric oxide and releases chloride ions. This is due to the presence of hydroxyl ions in the solutions which replaces the chloride ions. The reaction is given below:
$2FeC{{l}_{3}}+6O{{H}^{-}}\to F{{e}_{2}}{{O}_{3}}.3{{H}_{2}}O+6C{{l}^{-}}$

So, “Methylamine in water reacts with ferric chloride to precipitate hydrated ferric oxide” is true.

Note: Don’t get confused that when the ferric chloride reacts with hydroxyl ions, the precipitate is formed due to the formation $Fe{{(OH)}_{3}}$, instead is it formed due to the formation of hydrated ferric oxide $F{{e}_{2}}{{O}_{3}}.3{{H}_{2}}O$.