Advertisements
Advertisements
Question
A fresh air is composed of nitrogen N2 (78%) and oxygen O2 (21%). Find the rms speed of N2 and O2 at 20°C.
Solution
Absolute temperature T = 20°C + 273 = 293 K
Gas constant R = 8.32 J mol−1 K−1
For, Nitrogen (N2),
Molar mass (M) = 28 g per mol = 28 × 10−3 kg/mol
∴ vrms = `sqrt((3"RT")/"M") = sqrt((3 xx 8.32 xx 293)/(28 xx 10^-3)) = sqrt(7313.28/(28 xx 10^-3))`
`("v"_"rms")_("N"_2)` = 511 ms−1
For, Oxygen (O2),
Molar mass (M) = 32 g per mol = 32 × 10−3 kg/mol
∴ vrms = `sqrt((3"RT")/"M") = sqrt((3 xx 8.32 xx 293)/(32 xx 10^-3)) = sqrt(7313.28/(32 xx 10^-3))`
`("v"_"rms")_("O"_2)` = 478 ms−1
APPEARS IN
RELATED QUESTIONS
The velocity of the three molecules is 2 km s-1, 4 km s-1, 6 km s-1. Find (i) mean square velocity (ii) root mean square velocity.
If the rms speed of methane gas in the Jupiter’s atmosphere is 471.8 ms−1, shows that the surface temperature of Jupiter is sub-zero.
The number of molecules in 100 cc of gas at N.T.P. is ______ if the mass of each molecule is 4.556 x 10-25 kg and R.M.S. speed is 250 m/s.
The molecular weights of oxygen and hydrogen are 32 and 2 respectively. The root mean square velocities of oxygen and hydrogen at N.T.P. are in the ratio ______
The root mean square velocity of molecules of a gas is 200 m/s. What will be the root mean square velocity of the molecules, if the molecular weight is doubled and the absolute temperature is halved?
To what temperature should hydrogen at 227° C be cooled at constant pressure so that root mean square velocity of its molecule becomes half of its previous value?
The rms speed of oxygen molecule in a gas is u, If the temperature is doubled and the molecules dissociates into two atoms, the rms speed will be ______.
The temperature at which the molecules of nitrogen will have the same r.m.s. velocity as the molecules of oxygen at 327° C is ____________.
The root mean square speed of the molecules of a gas is proportional to ______.
[T =Absolute temperature of gas]
What will be the effect on the root mean square velocity of oxygen molecules if the temperature is doubled and the oxygen molecule dissociates into atomic oxygen?
