Question

Two gases, helium and X, are released from one end of an evacuated long cylinder at the same time. If it takes the helium atoms 3 times faster than gas X to effuse from one end of the cylinder to the other end, what is gas X?

Answer 1

Answer:

The correct answer is HOF gas.

Explanation:

Based on the given information, the helium atoms effuses three times faster in comparison to the gas X.

The rate of effusion is determined by,

r is inversely proportional to 1/√M, here M is the molecular mass of the gas.

and r is inversely proportional to 1/t, here t is the time taken for effusion.

Thus, t is directly proportional to √M

The molecular mass of He is 4.

tHe = tX/3 (Here tx is the time taken for gas X)

The molecular mass of X is not known.

tX/tHe =√Mx/MHe

3 = √Mx/4

By squaring both the sides we get,

9 = Mx/4

Mx = 36

36 is the molecular mass of gas HOF, that is, (1+16+19 = 36). Hence, the gas X is 36.