The rms speed of CO2 at a temperature T (in kelvin) is x cm s–1.At what temperature (in kelvin) the rms speed of nitrous oxide would be 4x cm s–1 ?

What are the difference between Diffusion and Effusion ?

Diffusion :The process of mixing of gases by random motion of the molecules is called diffusion.
Effusion: When gas is confined to a container at high pressure than the surrounding  atmosphere, it will
escape from a small hole which is opened in the container until the pressure outside and inside have been
equalised. This process is called effusion.