Question

${{\mathbf{C}}_{\mathbf{n}}}{{\mathbf{H}}_{{\mathbf{2n}} + {\mathbf{1}}}}{\left( {{\mathbf{OH}}}\right)_{\mathbf{3}}}$ is a general formula for trihydric alcohols-
A. True
B. False

Answer 1

Alcohols are organic molecules assembled from carbon (C), oxygen (O), and hydrogen (H) atoms. It is an organic compound with a hydroxyl $\left( { - OH} \right)$functional group on an aliphatic carbon atom. These are an important class of molecules with many scientific, medical, and industrial uses.

Step by step answer: Alcohols containing three hydroxyl $\left( { - OH} \right)$groups are known as trihydric alcohols. We know that a general formula is a type of empirical formula that represents the composition of any member of an entire class of compounds.
Here, we have to check whether the given general formula is correct for trihydric alcohols or not.
Let’s take an example. We know glycerin ($Propane - 1,2,3 - triol$) is a trihydric alcohol & its molecular formula is ${C_{3}}{H_5}{\left( {OH} \right)_3}$
From the above example it can be understood that
General formula for trihydric alcohols = ${C_n}{H_{2n - 1}}{\left( {OH} \right)_3}$​

Hence the given general formula in question for trihydric alcohols is incorrect. Option (B) will be correct choice.

Additional Information: According to the number of hydroxyl $\left( { - OH} \right)$groups, alcohols are divided into three classes:
-Alcohols containing one hydroxyl $\left( { - OH} \right)$ group are known as monohydric alcohols. Example- Ethanol
-Alcohols containing two hydroxyl $\left( { - OH} \right)$ groups are known as dihydric alcohols. Example- $1,2 - Ethanediol$ -Alcohols containing three hydroxyl\left( { - OH} \right)$$ groups are known as trihydric alcohols. Example- $1,2, - \Propanetriol$

Note: Students should be careful in deciding whether the alcohol is monohydric, or dihydric trihydric alcohols. They should carefully count the no. of hydroxyl $\left( { - OH} \right)$group attached to the carbon chain.