Question

Question 1)

It was important that the flask be completely dry before the unknown liquid was added so that water present would not vaporize when the flask was heated. A typical single drop of liquid water has a volume of approximately 0.05mL. Assuming the density of water is 1.0g/mL, if 6 drops of water were left in the flask how many moles of water would this be? ** Write answer in decimal form to four decimal places.**

Question 2)

Using your answer for question 1, what volume(in mL) would this amount of water occupy when vaporized at 100oC and 1atm?

** Write answer in decimal fom to one decimal place. **

Answer 1

Q 1 )

6 drops volume = 6 x 0.05 = 0.30 ml

density of water = 1 g/ml

mass of water = 0.30 x 1 = 0.30 g

moles of water = mass of water / molar mass

                         = 0.30 / 18

                         = 0.0167

Q 2)

n = 0.0167

P = 1atm

T = 273 + 100 = 373 K

P V = n RT

1 x V = 0.0167 x 0.0821 x 373

V = 0.5114 Litre

V = 511.4 ml

volume = 511.4 ml