The answer is: 3.61·10²⁴ atoms of oxygen.
n(NaNO₃) = 2.00 mol; amount of sodium nitrate.
In one molecule of sodium nitrate, there are three atoms of oxygen.
n(O) = 3 · 2 mol.
n(O) = 6.00 mol; amount of oxygen atoms.
N(O) = n(O) · Na.
Na = 6.022·10²³ 1/mol; Avogadro number.
N(O) = 6 mol · 6.022·10²³ 1/mol.
N(O) = 3.61·10²⁴; number of oxygen atoms.
