Answer:
46.004 g/mol
Step-by-step explanation:
Scottish physicist Thomas Graham formulated a law known as Graham's law of effusion in 1848. He conducted an experiment and found the relationship between the rate of effusion of a gas and its molar mass as:
![r=\sqrt {\frac {1}{M}}](https://img.qammunity.org/2020/formulas/chemistry/college/xa2ogfbwbn4ln7or2wew3t7x15rzy3fqsc.png)
where,
r is the rate of effusion of a gas
M is the molar mass of the gas.
Also, r = v/t
And for two gases taking different t₁ and t₂ to effuse, the formula is:
![\frac {t_2}{t_1}=\sqrt {\frac {M_2}{M_1}}](https://img.qammunity.org/2020/formulas/chemistry/college/y9z8uwrsoy6otic6u43187lsb9fm698dqk.png)
So,
For Neon :
= 8.61 minutes
= 20.1797 g/mol
For unkown gas:
= 13.0 minutes
= ? g/mol
![\frac {13.0}{8.61}=\sqrt {\frac {M_2}{20.1797}}](https://img.qammunity.org/2020/formulas/chemistry/college/dnplc7sew02gs5djukymenneof4q1zy7j6.png)
Molar mass of unknown gas = 46.004 g/mol