How many grams of oxygen are present in the magnesium oxide sample? (5 points) Show work.

Answer 1

How much does your sample of magnesium oxide weigh? For this answer, I will provide a made up amount to explain the process:

Let's say your sample of MgO is 10g.

For this conversion, we are trying to go from grams of MgO to grams of O.

It's kind of like asking, "If you have 10 pounds of apples, how much would all the seeds weigh?" We have 10g of MgO, how much of that weight comes from the O?

We will want to do the following conversions:

Dimensional Analysis plan: grams of MgO --> moles of MgO --> moles of O --> grams of oxygen

10 g MgO | 1 mol MgO | 1 mol O | 15.9 g O = 159 = 3.96 g of Oxygen

| 40.3 g MgO | 1 mol MgO | 1 mol O = 40.3

If you are unsure of how to use dimensional analysis to solve problems, or why these conversions make sense, I have a great lesson to explain. Just reach out!