Question

What will be the effect on the root mean square velocity of oxygen molecules if the temperature is doubled and oxygen molecule dissociates into atomic oxygen?

• A. The velocity of atomic oxygen remains same
• B. The velocity of atomic oxygen doubles
• C. The velocity of atomic oxygen becomes half
• D. The velocity of atomic oxygen becomes four times

Answer 1

Answer: (B)

The velocity of atomic oxygen doubles

Answer 2

$v$rms=$\sqrt{\frac{3RT}{M_0}}$
T is doubled and oxygen molecule is dissociated into atomic oxygen molar mass is halved.

So, $v'$rms=$\sqrt{\frac{3R×2T}{M_0/2}}$=2$v$rms

Therefore, the correct option is (B): velocity of atomic oxygen is doubled.