Question

Determine the number of molecules present in 5.60 mol of nitrogen dioxide, the number of atoms of oxygen, and the number of nitrogen atoms.

Please explain how.

Answer 1

Nitrogen dioxide is NO2 (where the number 2 is a subscript that indicates the number of atoms in one molecule).

Use Avogadro's number: 1 mol of molecules = 6.022 * 10^ 23 molecules.

So, in 5.6 mol of NO2 there are 5,6 mol * 6.022 * 10^23 molecules / mol = 33.72 * 10^23 molecules = 3.372 * 10^24 molecules of NO2.

There are the same number of N atoms (because there is 1 atom of N in 1 molecule) and there are the double of O atoms (becasue there are 2 atoms of O in 1 molecule) => 3.372 * 10 ^24 atomsof N and 6.744 atoms of O.

Answer: 3.372 * 10^24 molecules of NO2, 3.372 * 10^24 atoms of N and 6.744 atoms of O.