The number of hydrogen atoms in a disaccharide is twice the number of oxygen atoms. Disaccharide molecules are composed of linked monosaccharide units, which each have the general formula CnH2nOn, where n is the number of carbon atoms in the monosaccharide. For example, sucrose, a common disaccharide, is composed of glucose and fructose, which each have the formula C6H12O6. The linkage between the two monosaccharides in sucrose results in the formation of a disaccharide with the formula C12H22O11. Therefore, the number of hydrogen atoms in sucrose is twice the number of oxygen atoms (22/11 = 2).