Q.
The root mean square speed of the molecules of a diatomic gas is v. When the temperature is doubled, the molecules dissociate into two atoms. The new root mean square speed of the atom is
vrms=M3RT.
According to problem T will become T/2 and M will become M/2 so the value of vrms will increase by 4=2 times i.e., new root mean square velocity will be 2v.