CHEMISTRY
posted by Matt .
A glass vessel has a mass of 53.8718 g when evacuated (no air). When filled with a liquid of density 1.319 g mL1 it has a mass of 255.7390 g and when filled with an unknown gas at 752.3 torr and 16.12°C it has a mass of 54.2483 g. What is the molar mass of the gas, express your answer in scientific notation.?
...i'm confused about the three masses given. from the equation P=d(RT/MM), you don't need mass at all. please help?

You don't have the density, do you? The density given is that of a liquid.

how is liquid or the inital mass relevant to the question, if we're only concerned with the gas?

The liquid and mass and density of the liquid gives you a way of determining the volume of the container. Then the volume of the container and the mass of the gas gives you the density of the gas and from that the molar mass of the gas.
Respond to this Question
Similar Questions

Chemistry
mass of empty flask with stopper = 32.634 g mass of flask with water and stopper = 59.479 g density of the water = 0.9973 g/cm^3 mass of water = 26.845 g volume of water = 26.918 cm^3 the flask is then emptied and an unknown substance … 
Advance Chemistry
A series of measurements are made in order to determine the molar mass of an unknown gas. First, a large flask is evacuated and found to weigh 134.567 g. It is then filled with the gas to a pressure of 735 torr at 31°C and reweighed; … 
CHEM
The mass of an evacuated 255mL flask is 143.187g. The mass of the flask filled with 267 torr of an unknown gas at 25 degrees Celsius is 143.289g. Calculate the molar mass of the unknown gas. 
Chemistry
Calculate the mass of air in an airfilled tire and the mass of helium in a heliumfilled tire. What is the mass difference between the two? 
General Chemistry
At STP, a 5.00L flask filled with air has a mass of 543.251g. The air in the flask is replaced with another gas and the mass of the flask is 566.107g. The density of air is 1.29g/L. What is the gas that replaced the air? 
maths urgent please
A vessel is being filled at a variable and the volume of liquid in the vessel at any time t is given by V = A( 1 e^kt) V a) Show that dV/dt = k(AV) b) if one quarter of the vessel is filled in 5 minutes, what fraction is filled … 
Chemistry
1.) A convenient method of determining the volume of a container of irregular shape is to fill it with a liquid of known density and measure the mass. An empty Erlenmeyer flask marked "10 mL" weighs 26.3251 g. When filled with mercury, … 
Chemistry
A 50.0 mL graduated cylinder has a mass of 67.6 g. When it is filled with an unknown liquid to the 38.8 mL mark, the cylinder and liquid combined have a mass of 119.4 g. Calculate the density of the liquid in g/cm3. (1 mL = 1 cm3.) 
Chemistry
Having obtained the voume of the flask, she emptied the flask, dried it and filled it with an unknown whose density she wished to determine. The mass of the stoppered flask when completely filled with liquid was 56.796g. Find the density … 
SCIENCE
A flask weights 46.8 g when it is empty and 121.6 g when filled with water. When the same flask is filled with another liquid, the mass is 91.2 g. What is the density of the second liquid?