Question

The molecular mass of air, at standard pressure and temperature, is approximately 28.97 g/mol. Calculate the mass of 3.33 moles of air.

First, complete the unit conversion using dimensional analysis:

A ×
B
C
= ? g Air

A:
B:

Answer 1

A: 3.33 mol Air

B: 28.97 g Air

C: 1 mol Air

Answer 2

Mass = 96.47 g

Solution:

Data Given:

M.Mass = 28.97 g.mol⁻¹

Moles = 3.33 mol

Mass = ??

Formula Used:

Moles = Mass ÷ M.Mass

Solving for Mass,

Mass = Moles × M.Mass

Putting values,

Mass = 3.33 mol × 28.97 g.mol⁻¹

Mass = 96.4701 g

Rounding to four significant numbers,

Mass = 96.47 g