Question

How many moles of oxygen atoms are in 2.000 x 10^15 molecules of sulfur dioxide (SO2)?

Answer 1

6.64*10^(-9) moles of oxygen.

Explanation:

If we have N molecules, the number of moles is given by:

n = N/Nₐ

where Nₐ is the Avogadro's number:

Nₐ = 6.02214076*10^23

In 2.000*10^15 molecules of sulfur dioxide, we have:

n = (2.000*10^15)/(6.02214076*10^23) = 3.32*10^(-9) moles of sulfur dioxide.

Now, sulfur dioxide has two oxygens and a single sulfur.

Then a mole of sulfur dioxide has two moles of oxygen and a single mol of sulfur.

Then in 3.32*10^(-9) moles of sulfur dioxide, we have twice that amount moles of oxygen, or:

2*3.32*10^(-9) = 6.64*10^(-9) moles of oxygen.