Question

An empty 10 ml volumetric flask weighs 10.2634 g. when filled to the mark with distilled water and weighed again in the air at 20 oc, the mass is 20.2144 g. what is the true volume of the flask at 20 oc?

Answer 1

Answer is: the true volume of the flask is 10.2163 grams.
d(H₂O) = 0.9981 g/mL; density of water at 20°C.
V(H₂O) = 10 mL; volume of water.
m(H₂O) = d(H₂O) · V(H₂O).
m(H₂O) = 0.9981 g/mL · 10 mL.
m(H₂O) = 9.9981 g.
m(empty flask) = m(filled flask) - m(H₂O).
m(empty flask) = 20.2144 g - 9.9981 g.
m(empty flask) = 10.2163 g.

Answer 2

Explanation:

It is known that density of water at $20^{o}C$ is 998,29 $kg/m^{3}$ or 0.998 g/ml (as 1 $kg/m^{3}$ = 0.001 g/ml).

Therefore, calculate mass of water as follows.

        Mass of water = Final mass - initial mass

                                = 20.2144 g - 10.2634 g

                                = 9.951 g

As we known that density is the amount of mass present in a unit volume.                            

Mathematically,       Density = $\frac{mass}{volume}$

Therefore, putting the given values into the above formula we will calculate the volume as follows.

                         Density = $\frac{mass}{volume}$

                         0.998 g/ml = $\frac{9.951 g}{Volume}$

                        Volume = 9.97 ml

Thus, we can conclude that volume of the flask at $20^{o}C$ is 9.97 ml.