Question

The rms speed of oxygen molecules in a gas is v. If the temperature is doubled and the oxygen molecules dissociate into oxygen atoms, the rms speed will become
(a) v
(b) v√2
(c) 2v
(d) 4v.

Answer 1

Answer:

Option c

Explanation:

Answer 2

Answer is Option (c)

Explanation:

• The Root Mean Square (rms) speed of oxygen molecules in a gas = $V_{rms}$

• Let T be the initial temperature before dissociation
• T' temperature after dissociation into oxygen atoms.

So,  

$V_{rms} = \frac {3RT}{M}$

$V_{rms}^{'} = \frac {3RT'}{M'}$

T' = 2T

$M' = \frac {M}{2}$

$V_{rms}^{'} = 2V_{rms}$

So, Root Mean Square Speed is 2v