How many moles of br2 (l) (mm = 159.80 g/mol) are in 13.9 ml of liquid bromine? the density of br2 (l) is 3.12 g/ml?

Moles = 0.271 mol

Solution:

Step 1: Calculate Mass of Br₂ as;

Density = Mass : Volume

Solving for Mass,

Mass = Density * Volume

Putting values,

Mass = 3.12 g. mL⁻¹ * 13.9 mL

Mass = 43.36 g

Step 2: Calculate Moles of Br₂ as;

Moles = Mass : M. Mass

Putting values,

Moles = 43.36 g : 159.80 g. mol⁻¹

Moles = 0.271 mol