27.94 g/mole is the molar mass of the unknown gas.
Use Graham's Law, which indicates that the square root of a gas's molar mass determines its rate of effusion.
The following equation compares two distinct gases, (a) and (b), and expresses this:
sqrt(M(b)/M) = R(a)/R(b) (a)
R is the effusion rate.
square root = sqrt
the molar mass, M
In response to your query, if gas (a) is the unknown gas and Xe(M = 131 g/mol) is the second gas, we have:
sqrt(M(Xe)/M(a) = 2.165, where R(a)/R(Xe)
Square both sides, and you get:
(2.165)² = 131 g/mol/ M (a)
M(a)(2.165)² = 131
M(a) is equal to 131/(2.165)² = 27.94 g/mol.
Having a molar mass of 27.94 g/mol, the unknown gas.
Learn more about Graham's law of effusion here https://brainly.com/question/22359712
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