22.17 grams of Mercury (II) Nitrate, Hg(NO3)2, reacts with an excess of Potassium, K. How many grams of Mercury is formed.
Hg(NO3)2 + 2 K = 2 KNO3 + Hg

Mass = 14.0 g

Explanation:

Given data:

Mass of mercury nitrate = 22.17 g

Mass of mercury formed = ?

Solution:

Chemical equation:

Hg(NO₃)₂ + 2K    →    2KNO₃ + Hg

Number of moles of mercury nitrate:

Number of moles = mass/molar mass

Number of moles = 22.17 g / 324.6 g/mol

Number of moles = 0.07 mol

Now we will compare the moles of Hg(NO₃)₂ and mercury.

                Hg(NO₃)₂       :        Hg

                     1                :          1

                  0.07             :       0.07

Mass of mercury:

Mass = number of moles × molar mass

Mass = 0.07 mol × 200.6 g/mol

Mass = 14.0 g