Question

Use complete sentences to explain how you determined the mass of oxygen in the compound produced in the virtual lab, and how the mass of each element can be used to determine the empirical formula of the compound.

Answer 1

Well, I didn't do the virtual lab, but you can find the mass of oxygen on the periodic table by looking at its mass number.

Answer 2

Start with the number of grams of each element, given in the problem.
If percentages are given, assume that the total mass is 100 grams so that

the mass of each element = the percent given.
Convert the mass of each element to moles using the molar mass from the periodic table.
Divide each mole value by the smallest number of moles calculated.
Round to the nearest whole number. This is the mole ratio of the elements and is

represented by subscripts in the empirical formula.
If the number is too far to round (x.1 ~ x.9), then multiply each solution by the same

factor to get the lowest whole number multiple.
e.g. If one solution is 1.5, then multiply each solution in the problem by 2 to get 3.
e.g. If one solution is 1.25, then multiply each solution in the problem by 4 to get 5.

Answer 3

Also, you are studying the wrong subject, this is math, not chemistry.