1. How many atoms of oxygen are present in 0.04 mole NaNO3? 2. How many moles of nitrogen atoms are present in 10.5g of N2O5?

3. How many atoms of oxygen are present in 50g of Fe(H20)2(S04)3? Please answer fast

1. 7.227x10²⁴ O atoms

2. 0.1944 mol

3. 3.18x10²³ atoms

Explanation:

1. To solve this problem we need to use Avogadro's number, which states the number of molecules that are in 1 mol of a substance:

There are 3 O atoms per NaNO₃ molecule, thus the answer is (3* 2.409x10²⁴) 7.227x10²⁴ atoms.

2. First we convert 10.5 g of N₂O₅ into moles, using its molar mass:

There are 2 N moles per N₂O₅ mol, thus the answer is (2*0.0972) 0.1944 mol.

3. First we convert grams into moles:

Then we use Avogadro's number:

There are 14 O atoms per Fe(H₂O)₂(SO₄)₃ molecule, so the answer is (7.95x10²² * 4) 3.18x10²³ atoms.