What is the name of the structures that move substances across a tract surface?

Aspirin has a density of 1.40 g/cm3 what is the volume in cubic centimeters of a tablet weighing 320 mg ?

The molality of calcium chloride (cacl2) in an aqueous solution is 2.46 m. what is mole fraction of the solute?

You just calculated that the heat of fusion for chloromethane is 6400 j/mol. the heat of fusion for hydrogen is 120 j/mol.? which of the following account for this difference? more than one correcta. chloromethane can absorb more energy at the same temperature. b. hydrogen has stronger intermolecular forces than chloromethane. c. hydrogen molecules can pack more closely than chloromethane molecules. d. chloromethane experiences dipole-dipole interactions. e. chloromethane has a higher molar mass than hydrogen.