Answer to Question #113199 in Chemistry for Mohammed Al-fatlawi

Question

How many atoms of nitrogen are in 10.0g of N2O5 ?

Answer 1

The molecular weight of N₂O₅ equals:

Mr(N₂O₅) = (2 × 13 g/mol) + (5 × 16 g/mol) = 108 g/mol

The number of moles of 10 g of N₂O₅ euals:

n = m / Mr = 10 g / 108 g/mol = 0.09 mol

As 1 mole of any substance contains 6.022 × 10²³ particles, 0.09 mol of N₂O₅ contains:

N(N₂O₅) = 0.09 mol × 6.022 × 10²³ = 5.4 × 10²² molecules.

As one molecule of N₂O₅ contains two atoms of nitrogen:

N(N) = 5.4 × 10²² × 2 = 1.1 × 10²³ atoms of nitrogen

Answer: 1.1 × 10²³ atoms of nitrogen