Question

2. Mercury (II) oxide decomposes into mercury and oxygen gas according to the following

Answer 1

Answer:

7.8 moles are needed.

Explanation:

Given data:

Mass of oxygen produced = 125 g

Number of moles of mercury oxide needed = ?

Solution:

Chemical equation;

2HgO → 2Hg + O₂

Number of moles of oxygen:

Number of moles = mass/ molar mass

Number of moles = 125 g/ 32 g/mol

Number of moles = 3.9 mol

Now we will compare the moles of oxygen with mercury oxide.

                       O₂         :         HgO

                        1           :             2

                     3.9          :              2×3.9 = 7.8 mol