Help is needed for converting units of a simple formula

[han_123]

How would you convert a volume mixing ratio [m3/m3] to the units of [molecules/cm3]? The temperature is given to be 293K and the air density is 1 kg/m3. Please help!

 

[anuttarasammyak]

[m3/m3] has no physical dimension but [molecules/cm3] has physical dimension of L^-3. I am afraid some more details of the exercise are required to help you.

 

[Borek]

Do you know Avogadro's hypothesis?

And do you know how to convert gas volume to number of moles? Number of moles to number of molecules?

 

[han_123]

Do you know Avogadro's hypothesis?

And do you know how to convert gas volume to number of moles? Number of moles to number of molecules?

Hi! Well not exactly. I know there is the ideal gas formula PV = nRT and that a mole contains the Avogadro number of molecules.

However, I am confused about how to convert a volume mixing ratio [m3/m3] or [mol/mol] to the units of [molecules/cm3] when only the temperature is given to be 293K and the air density is 1 kg/m3.

The goal is to find whenever a gas is mixed into an airspace at a certain ratio then how many molecules of that gas are to be found in one cm3.

 

[han_123]

[m3/m3] has no physical dimension but [molecules/cm3] has physical dimension of L^-3. I am afraid some more details of the exercise are required to help you.

The volume mixing ratio can also be given in [mol/mol]. How do you convert a mol of gas into the number of molecules when only the air density and temperature are given?

The goal is to find whenever a gas is mixed into an airspace at a certain ratio then how many molecules of that gas are to be found in one cm3.

 

[Borek]

Hint: density at a given temperature is enough to find the pressure.