Identify Gas based on Temperature and Speed of Sound

[infinitas]

So the question is, How would I go about identifying an unknown monatomic gas if you have measured its temperature and the speed of sound in the gas.

I was thinking of using the ideal gas law to determine mass of a single molecule in kilograms or its molar mass, then from there somehow calculate its atomic mass? Am I going in the right direction? If so, I'm not sure how to get from its molecular mass to its atomic mass.

 

[chemisttree]

Use http://hyperphysics.phy-astr.gsu.edu/Hbase/sound/souspe3.html" instead...

 

[infinitas]

Right. I know how to calculate M. The issue is getting from M to the actual element.

 

[chemisttree]

Use http://www.webelements.com/"

 

[DeeNos]

Yes, you are definitely on the right track. The ideal gas law, which relates the pressure, volume, temperature, and number of moles of a gas, can be used to determine the molar mass of a gas. This molar mass can then be used to calculate the atomic mass of the gas.

To start, you would need to rearrange the ideal gas law to solve for the number of moles (n) of the gas:

n = (PV)/(RT)

where P is the pressure, V is the volume, R is the gas constant, and T is the temperature.

Next, you would need to determine the molar mass of the gas by dividing the mass of the gas (m) by the number of moles (n):

Molar mass = m/n

Once you have the molar mass, you can use the atomic mass unit (amu) to calculate the atomic mass of the gas. The atomic mass unit is defined as 1/12th of the mass of a carbon-12 atom. So, for example, if the molar mass of the gas is 28 g/mol, then the atomic mass would be 28 amu.

However, it's important to note that this method will only work for monatomic gases, which have a single atom in their molecules. For diatomic gases, such as oxygen (O2) or nitrogen (N2), the molar mass and atomic mass would be the same. But for more complex molecules, this method may not be accurate.

Another approach you could take is to use the speed of sound in the gas to determine its molecular weight. The speed of sound in a gas is related to the average speed of the gas molecules, which in turn is related to the molecular weight. You could use this information to narrow down the possible options for the unknown gas.

In general, identifying an unknown gas based on its temperature and speed of sound would require a combination of different methods, including the ideal gas law, knowledge of the atomic and molecular structure of the gas, and possibly experimental data. It may also be helpful to compare your results with known data for different gases to confirm your identification.