Bvitamins are a group of water soluble compounds that are important in cell metabolism. each one has a different chemical structure. rank, in order of increasing molar mass, the following b vitamins listed below. drag and drop into the appropriate area) items in order smallest molar mass tamin b6, idoxine vitamin b2, ribolavin vitamin 81, thiamine 2 tamin b5, totheric acid tamin 87 biotin 3 4 largest molar mass