Answer:
b. SF₆
Explanation:
Graham's law states that the rate of diffusion of a gas is inversely proportional to the square root of its molecular mass,
As molecular mass of O₂ is 32g/mol, the diffusion is equal to (Assuming constant of proportionality of 1):
1/√32 = 0,1768.
As this diffusion is 2,14 times faster than diffusion of the unknown gas, diffusion of the unknown gas is:
0,1768/2,14 = 0,0826
Know, this diffusion times √molec. mass of the unknown gas must be 1.
That is:
0,0826 = 1/√molec. mass
0,0826√molec. mass = 1
√molec. mass = 12,1
molecular mass of the unknown gas is: 12,1² = 146g/mol
Cl₂ has a molecular mass of 70,9 g/mol; SF₆ of 146g/mol; kr of 83,8g/mol; UF₆ of 352 g/mol and Xe of 131,3
That means the uknown gas is:
b. SF₆
I hope it helps!
