Question

The rms speed of molecules of hydrogen at 27 degrees * C is v. Then the temperature at which the rms speed of hydrogen molecules will be 2v, is
150 K
600 K
1200 K
279 K​​

Answer 1

Given : RMS speed of molecule = v

Temperature = 27° C

Find : Final temperature.

Solution : RMS speed is calculated by the help of formula v² = 3kT/m. In the formula, v is RMS speed, k is Boltzmann constant, T is temperature and m is molar mass.

Converting temperature in Kelvin : 273 + 27 = 300 K.

To find out the RMS speed, formula used will be -

v1²/v2² = T1/T2

Keeping the values in equation-

v²/(2v)²= T1/T2

v²/4v² = 300/T2

T2 = 300*4

T2 = 1200 K

Hence, the temperature at which the rms speed of hydrogen molecules will be 2v is - 1200 K.