# Lab 15 Molecular Mass of a Volatile liquid Tasnuva Israil 02/14/2012

```Lab 15
Molecular Mass of a Volatile liquid
Tasnuva Israil
02/14/2012
1.)
If the outside of your flask is not dry when the first mass determination is
made and it is dried for the second mass determination, what effect will that
If the outside of the flask is not dry for the first mass determination and it is
dried for the second mass determination this will affect my results. The mass
of the aluminum cap and the empty will be greater and it will cause the
molecular mass to decrease.
2.) What will be the effect on your results if all the liquid is not vaporized while
heating?
If all the liquid is not vaporized while heating that means the mass of the
vapor is higher than the mass of the empty flask. That causes the molecular
mass to increase.
3.)
Which assumption would lead to the greatest error in your results, explain
why?
(A)
assume temperature is 25 degress celcius
(B)
assume the flask volume is exactly 125 mL
That will cause a greater error in my results because it can cause a different amount of
liquid to be used which causes an inaccurate change in the colume used. Ultimately, that
causes a great variable in the mass of the vapor used.
(C)
assume the barometric pressure is exactly 760.
```