Please help me this is urgent chemistry?

2. It was important that the flask used in this experiment be completely dry before the unknown liquid was added, so that any water present would not vaporize when the flask was heated. A typical drop of water has a volume of about 0.05 mL. uming the density of liquid water is 1.0 g/mL, how many moles of water are in one drop of liquid? What volume would this amount of water occupy when vaporized at 100�C and 1 atm? What error would this introduce into the determination of the molar m of the unknown?