# Isaac physics G2.6 a level physics thermodynamics

hey could anyone help me out with this question please?

A tyre contains 800cm^3 of air at a pressure of about 5.0×10^5 Pa at 9 degrees C. After a cycle ride, the volume is 760cm^3 , the temperature is now 25∘C, and the pressure is 4.0×10^5 Pa. What percentage of the gas molecules have leaked out?
Original post by millyfreeman_
hey could anyone help me out with this question please?

A tyre contains 800cm^3 of air at a pressure of about 5.0×10^5 Pa at 9 degrees C. After a cycle ride, the volume is 760cm^3 , the temperature is now 25∘C, and the pressure is 4.0×10^5 Pa. What percentage of the gas molecules have leaked out?

I'd think about using the ideal gas equation

PV=nRT

Remember to convert temperatures to an absolute temperature unit i.e. Kelvin
Original post by millyfreeman_
hey could anyone help me out with this question please?

A tyre contains 800cm^3 of air at a pressure of about 5.0×10^5 Pa at 9 degrees C. After a cycle ride, the volume is 760cm^3 , the temperature is now 25∘C, and the pressure is 4.0×10^5 Pa. What percentage of the gas molecules have leaked out?

You know the equation PV=NkT.
This is the ideal gas equation and connects all gas laws. You can rearrange the equation for the number of molecules. Find the number of molecules present before and after. Find the difference and put it over the original and times by 100 to find the percentage difference.

N=PV/kT
N before=…
N after=…