Question

A gas made up of atoms escapes through a pinhole 0.392 times as fast as Ne gas. Write the chemical formula of the gas.

Answer 1

Answer: The chemical formula of the gas is Xenon.

Step-by-step explanation:

From Graham's law of effusion rates, the rate of effusion of a gas is inversely proportional to the square root of its molar mass.

`(rate_1)/(rate_2)=\sqrt{(M_2)/(M_1)}`

Given: Rate of unknown gas =
`0.392* R_(Ne)`

Putting the values in the formula:

`(rate_X)/(rate_(Ne))=\sqrt{(M_(Ne))/(M_X)}`

`0.392=\sqrt{(20.17)/(M_X)}`

Squaring both sides:

`0.154=(20.17)/(M_X)`

`M_X=131g/mol`

As Xenon (Xe) has molar mass of 131g/mol, Thus the chemical formula of the gas is Xenon.