If a gas effuses 2.17 times faster than Xe, what is its molar mass?

Molar mass = 27.88 g/mol

Explanation:

The relationship between how gases effuses is given by Graham's law of effusion. This law is given as;

Rg / Rxe  =   (Mxe / Mg)

Where;

Rg = Rate of effusion of gas g

RXe = Rate of effusion of Xe

Mxe = Molar mass of Xe = 131.29 g/mol

Mg = Molar mass of gas g

From the question;

Rg : Rxe = 2.17 : 1

Rg / Rxe = 2.17 / 1 = 2.17

2.17 = 131.29 / Mg

Squaring both sides

4.7089 = 131.29 / Mg

Mg = 131.29 / 4.7089

Mg = 27.88 g/mol

hey there!

mass = 6.75 g

volume =   9 cm³

therefore:

d = mass / volume

d   = 6.75 / 9

d = 0.7 g/cm³

answer b