Glucose has a molecular mass of 180 daltons. to make a 2-molar (2 m) solution of glucose,

The molality of a substance is the moles of the substance present in 1000mL or 1L or 1Kg of water. 1L of water is equivalent to 1Kg of water as the density of water is 1g/mL. The molecular mass of a substance is represent the amount of the substance present in 1 mole of the compound. Here the molar mass of glucose is 180 daltons thus 1 mole of glucose is equivalent to 180 daltons. To prepare 1 molar glucose solution 180 daltons of glucose have to dissolve in 1L of water. So to prepare 2 molar glucose solution (180×2) = 360 daltons of glucose have to dissolve in 1000mL or 1L or 1Kg of water.