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

             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