DensityOfGases

Density of Gases: 

Density of Gases Different gases have different densities. Why is this important? How do we measure densities? What causes the densities of different gases to be different? Do denser gases have more particles per liter? Or do gases have the same particles per liter but their particles' mass differ?

Why is gas density important?: 

Why is gas density important? Ask the folks on the Hindenburg Pictures from Navy Lakehurst Historical Society, Inc

How to measure gas density: 

How to measure gas density First, find the mass of a given volume of “nothing” We can use an evacuated flask or a syringe with a “fixed” plunger. Then we put the same volume of gas into the flask or syringe and find its mass The difference between the empty container and the container with the gas is the mass of that volume of gas.

Specimen Data: 

Specimen Data Gases: Oxygen Air Carbon Dioxide Methane Helium For 50 mL of gas 25 °C 65 mg 59 mg 90 mg 33 mg 8 mg

Gas Densities: 

Gas Densities

Gas Densities: 

Gas Densities

Gas Densities: 

Gas Densities

What causes the difference in densities?: 

What causes the difference in densities? There are only two possibilities (or some combination of these two possibilities).

Do denser gases have more particles per liter?: 

Do denser gases have more particles per liter? Helium Carbon dioxide Carbon dioxide would have 11 times the number of particles of helium in the same container

Or do gases have the same particles per liter but their particles' mass differ?: 

Or do gases have the same particles per liter but their particles' mass differ? Helium Carbon dioxide Carbon dioxide would have particles 22 times heavier than hydrogen or 11 times heavier than helium

Solving the Riddle: 

Solving the Riddle We need to count the number of particles in equal volumes of two gases, at the same temperature and pressure If one has a lot more particles than another, then we have situation #1 Helium Carbon dioxide

Solving the Riddle: 

Solving the Riddle We need to count the number of particles in equal volumes of two gases, at the same temperature and pressure If the two gases have the same number of particles, then we have situation #2 Helium Carbon dioxide

The Contenders: 

The Contenders Helium Carbon dioxide Helium Carbon dioxide More Particles More Mass