ANSWER
The number of moles of oxygen formed is 7.06 moles
EXPLANATION
Given that
The number of moles of mercury (II) oxide is 14.12 moles
Follow the steps below to find the number of moles of oxygen
Step 1; Write the balanced equation for the decomposition of the reaction
[tex]\text{ 2HgO }\rightarrow\text{ 2Hg}_{(s)}\text{ + O}_{2(g)}[/tex]In the reaction above, 2 moles HgO decompose to produce 2 moles Hg and 1 mole O2
Step 2; Find the number of moles of oxygen using a stoichiometry ratio
Let x represents the number of moles of oxygen
[tex]\begin{gathered} \text{ 2 moles HgO }\rightarrow\text{ 1 mole O}_2 \\ \text{ 14.12 moles HgO}\rightarrow\text{ x mole O}_2 \\ \text{ cross multiply} \\ \text{ 2 moles HgO }\times\text{ x mole O}_2\text{ }=\text{ 1 mole O}_2\times\text{ 14.12 moles HgO} \\ \text{ Isolate x} \\ \text{ x = }\frac{1\text{ mole O}_2\times14.12moles\cancel{HgO}}{2moles\cancel{HgO}} \\ \text{ x = }\frac{14.12}{2} \\ \text{ x = 7.06 moles} \end{gathered}[/tex]Therefore, the number of moles of oxygen formed is 7.06 moles