Question

Molecular weight of CO2 gas Lab Questions:

I need to find some calculations but i'm pretty lost,

Data:
mass of foil+flask w/ air : 125.525g
temp of dry air in flask: 22.0 degrees Celsius
Barometric Pressure: 0.993atm
Density of dry: 1.189 g/ml
mass of foil+flask w/ CO2 : 125.695g
mass of foil+flask w/ CO2 after 15min: 125.698g
temp of CO2 in flask: 22.0
mass of flask w/ water and foil: 407.35g
temp of water: 21.9
density of water at above temp: 0.9978g/ml

find the mass of empty flask.
find the mass of CO2 in flask.
Find the experimental molecular weight of CO2

Answer 1

(flask + foil + water) - (flask + foil + air) = volume of flask (density water- density air)

this will give you flask volume, which will help you get air weight, thus flask + foil weight and will help you find density and volume and mass of CO2.

pV = nRT along with mass of CO2 should let you get n, which is number of moles, from which the weight of CO2 will give you the molecular weight,

I do not see how to get the mass of the foil, to isolate the weight of the flask.

Answer 2

The difference (flask+foil+water)-(flask+foil+air) is due to the volume of the flask times the difference in density between water and air,

so volume of flask = [(flask+foil+water)-(flask+foil+air)]/(density water-density air)

volume of flask=volume of CO2