Question

Paige heated 3.00 g mercury (II) oxide (HgO, 216.59 g/mol) to form mercury (Hg, 200.59 g/mol) and oxygen (O2, 32.00 g/mol). She collected 0.195 g oxygen. What was the percent yield of oxygen?

Answer 1

87.8% - Just checked it on edg

Answer 2

We first write the chemical equation:

2HgO → 2Hg + O₂

Next, we calculate the moles of HgO present:

moles = 3 / 216.59
moles = 0.014

Each mole of oxygen gas needs 2 moles of HgO to be produced.
Theoretical moles of oxygen gas produced = 0.014 / 2
= 0.007

Theoretical mass of oxygen = 0.007 x 32 = 0.224 grams

Percentage yield = actual yield / theoretical yield x 100
= 0.195 / 0.224 x 100
= 87.0%