Question

A 0.334 g sample of an unknown compound occupies 245 ml at 298 K and 1.22 atm. What is the molar mass of the unknown compound.

Answer 1

27.4 g/mol

Step-by-step explanation:

Assuming the compound is a gas and that it behaves ideally, we can solve this problem by using the PV=nRT formula, where:

• P = 1.22 atm

• V = 245 mL ⇒ 245 mL / 1000 = 0.245 L

• n = ?

• R = 0.082 atm·L·mol⁻¹·K⁻¹

• T = 298 K

Inputting the data:

• 1.22 atm * 0.245 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 298 K

Solving for n:

• n = 0.0122 mol

With the calculated number of moles and given mass, we calculate the molar mass:

• 0.334 g / 0.0122 mol = 27.4 g/mol