Final answer:
The hydrogen to oxygen ratio is 2:1 for starch, single sugars, and water, meaning option (A) is correct: The ratio is the same in all of them. Disaccharides also have a similar ratio when considering the entire structure.
Step-by-step explanation:
The ratio of hydrogen to oxygen atoms in starch compared with double sugars, single sugars, and water can be understood by looking at the general chemical formula for carbohydrates: (CH2O)n, where n is the number of carbon atoms. This formula indicates a ratio of carbon to hydrogen to oxygen of 1:2:1 for carbohydrates, meaning for every carbon and oxygen atom, there are two hydrogen atoms. Starch, being a polysaccharide, is composed of repeating units of glucose with the formula C6H12O6.
Single sugars (monosaccharides) like glucose also have this ratio. Double sugars (disaccharides) such as sucrose (table sugar) comprising two monosaccharides will have a formula that is an integration of the individual monosaccharide formulas less one water molecule (H2O) due to the condensation reaction that forms them. Therefore, starch and single sugars will have the same ratio of hydrogen to oxygen, but double sugars will have a slightly lower ratio because of the removal of a water molecule during their formation. Finally, water (H2O) has a fixed 2:1 ratio of hydrogen to oxygen.
The correct answer to the question is (A): The ratio is the same in all of them. This refers to the fact that the ratio of hydrogen to oxygen is 2:1 in starch, single sugars, and water. Although double sugars also essentially adhere to this ratio, their formation results in the removal of a water molecule, slightly altering the overall formula but not the basic molar ratio of H to O, provided the entire disaccharide structure is considered.