chemistry/ molarity, molality
posted by christine .
A solution is made by mixing 20.0 mL of C6H5CH3, d=.867g/mL, with 140.0mL of C6H6, d=.874g/mL. assuming that the volumes add upon mixing, what is the molarity? what is the molality?
i know that molarity= moles/L and molality= moles sol/kg solvent... but im not sure which numbers to use... help please
Using the density of each calculate the mass of each material used.
From the mass of each calculate the number of moles of each.
Add the two volumes to get the total volume, and you can now calculate the molarity of each.
Add the two masses and you can now calculate the molality of each.
A tip...don't forget leading zeros
e.g. d=0.867g/mL is clearer than d=.867g/mL