Question

Ceric ammonium nitrate and CHCl₃/alc. KOH are used for the identification of functional groups present in _________and________ respectively.

• A. Alcohol, amine
• B. Amine, alcohol
• C. Alcohol, phenol
• D. Amine, phenol

Answer 1

The correct option is A

Alcohol, amine

The explanation for the correct answer.

(A) - Alcohol, amine

Ceric ammonium nitrate $\left(\left({\mathrm{NH}}_4\right)\left[\mathrm{Ce}{\left({\mathrm{NO}}_3\right)}_6\right]\right)$ is a test that is given by the (-OH) group.

So as we can see in option (a) alcohol(R-OH) and amine(R-NH₂) are given which will give a positive test for ceric ammonium nitrate test.

$$\begin{gathered} 3\mathrm{R}-\mathrm{OH}\left(\mathrm{l}\right)+\left({\mathrm{NH}}_4\left)\right[\mathrm{Ce}{\left({\mathrm{NO}}_3\right)}_6]\right)\left(\mathrm{aq}\right)\to \left[\mathrm{Ce}{\left({\mathrm{NO}}_3\right)}_4{(\mathrm{R}-\mathrm{OH})}_3\right]\left(\mathrm{aq}\right)+2{\mathrm{NH}}_4{\mathrm{NO}}_3\left(\mathrm{aq}\right) \\ \mathrm{alcohol}\mathrm{wine}\mathrm{red}\mathrm{complex} \end{gathered}$$

As we can see alcohol gives the wine a red complex which is used as a test for alcohol.

In the same manner, amines also give the test for ceric ammonium nitrate.

$$\begin{gathered} 3\mathrm{Ar}-\mathrm{OH}\left(\mathrm{l}\right)+\left({\mathrm{NH}}_4\left)\right[\mathrm{Ce}{\left({\mathrm{NO}}_3\right)}_6]\right)\left(\mathrm{aq}\right)\to \left[\mathrm{Ce}{\left({\mathrm{NO}}_3\right)}_4{(\mathrm{Ar}-\mathrm{OH})}_3\right]\left(\mathrm{aq}\right)+2{\mathrm{NH}}_4{\mathrm{NO}}_3\left(\mathrm{aq}\right) \\ \mathrm{alcohol}\mathrm{wine}\mathrm{red}\mathrm{complex} \end{gathered}$$

The explanation for the incorrect answer.

(B)- Amine, alcohol

• Hinsberg test is used to identify amines.
• To determine whether alcohol is present or not, take the alcohol-free water, and neutral liquid, and add a solid phosphorous (V) chloride.
• A burst of acidic steamy hydrogen chloride fumes specifies an alcohol presence.

(C) -Alcohol, phenol

Test for alcohol

• Sodium metal test - sodium is an active metal which alcohols react to form a colourless solution of sodium alkoxide along with the formation of brisk effervescence due to liberation of hydrogen gas.

Test for phenol

• A dark-coloured complex is formed when phenol reacts with a neutral ferric chloride solution.

(D) -Amine, phenol

Test for amine

• Hinsberg test is used to identify amines.
• To determine whether alcohol is present or not, take the alcohol-free water, and neutral liquid, and add a solid phosphorous (V) chloride.
• A burst of acidic steamy hydrogen chloride fumes specifies an alcohol presence.

Test for alcohol

• Sodium metal test - sodium is an active metal which alcohols react to form a colourless solution of sodium alkoxide along with the formation of brisk effervescence due to liberation of hydrogen gas.

Hence, option (A) is the correct answer.