Question

How many atoms of mercury are present in 3.4 cubic centimeters of liquid mercury? the density of mercury is 13.55 g/cc?

Answer 1

1.37 × 10²³ Atoms of Mercury

Solution:

Step 1: Calculate Mass of Mercury using following formula,

Density = Mass ÷ Volume

Solving for Mass,

Mass = Density × Volume

Putting values,

Mass = 13.55 g.cm⁻³ × 3.4 cm³ ∴ 1 cm³ = 1 cc

Mass = 46.07 g

Step 2: Calculating number of Moles using following formula;

Moles = Mass ÷ M.mass

Putting values,

Moles = 46.07 g ÷ 200.59 g.mol⁻¹

Moles = 0.229 mol

Step 3: Calculating Number of Atoms using following formula;

Number of atoms = Moles × 6.022 ×10²³

Putting value of moles,

Number of Atoms = 0.229 mol × 6.022 × 10²³

Number of Atoms = 1.37 × 10²³ Atoms of Hg