Question

Do all carbohydrates have the formula `C_nH_(2m)O_m`?

Answer 1

Although carbohydrates are essentially hydrated carbons (i.e. each carbon is hydrated with a water molecule), sugars like deoxyribose sugar ( `C_5H_{10}O_4`) are also considered carbohydrate.

Explanation:

It is easier to view carbohydrate formula as `C_n(H_2O)_m` in order to see that it is hydrated carbon. In a condensation reaction where a disaccharide is formed, 1 molecule of water leave thereby giving `m=n-1`

However, in the case of deoxyribose, one of the carbon molecule is without an oxygen thereby becoming an exception to the formula.