Q.

The r.m.s. speed of oxygen molecules at 47°C is equal to that of the hydrogen molecules kept at ______ °C.

(Mass of oxygen molecule / mass of hydrogen molecule = 32/2)     [2026]

1 −235  
2 −253  
3 −20  
4 −100  

Ans.

(2)

Vrms=3RTM

VrmsO2=VrmsH2

TO2=273+47=320K

3RTO2MO2=3RTH2MH2

TO2MO2=TH2MH2

32032=TH22

TH2=20K

TH2=-253°C