Question

The general formula of carbohydrates is:
A.\[{C_n}{H_{2n + 1}}O\]
B.\[{C_n}{H_{2n}}O\]
C.\[{C_n}{({H_2}O)_n}\]
D.\[{C_n}{({H_2}O)_{2n}}\]

Answer 1

Hint: Glucose is one of most important carbohydrates having the structural formula \[{C_6}{H_{12}}{O_6}\]. Its simplest or empirical formula comes out to be \[C{H_2}O\].

Complete step by step answer:
The empirical formula of a carbohydrate comes from the fact that a carbohydrate is a biomolecule consists of carbon(C), hydrogen(H) and oxygen(O) atoms, with a hydrogen-oxygen atom ratio of 2:1 and the ratio of carbon to hydrogen to oxygen is 1:2:1. So we can refer to it as carbon water or hydrates of carbon and represent it as \[{(C{H_2}O)_n}\], where n can be any number greater than 3. Therefore, it can also be written as \[{C_n}{({H_2}O)_n}\]. This formula explains the meaning of the term ‘carbohydrate’ i.e. the components are carbon for carbon and water for hydrate. The simplest carbohydrate thus formed by putting n as 1 is glucose, \[{C_6}{H_{12}}{O_6}\].

Hence, the correct option is (C).

Note:
This general formula has many exceptions. For example, acetic acid (\[C{H_3}COOH\]) will fit in the general formula described for carbohydrates but it is not a carbohydrate. Similarly, formaldehyde (HCHO) is not a carbohydrate yet falls under this category.