Moles and Avogadro’s Numbers

One methane molecule contains ten protons. Thus, one mole contains 10 × Avogadro's number of protons.

The balanced equation directly provides the ratio.

One mole always contains 6.022 × 10²³ elementary particles.

One mole of nitrogen produces two moles of nitrogen dioxide. Therefore, 0.5 mole yields one mole.

One mole occupies 22.4 dm³ at STP, so two moles occupy 44.8 dm³.

Forty-eight grams of magnesium equal two moles, producing two moles of MgO. The mass becomes 80 g.

Each NH₃ molecule contains three hydrogen atoms; therefore one mole of NH₃ contains three moles of hydrogen atoms.

Half a mole contains half of Avogadro's number of molecules.

Glucose contains six carbon atoms per molecule. Therefore, 0.5 mole of carbon atoms corresponds to 0.5 ÷ 6 = 0.083 mole of glucose.

Hydrogen and water have a 1:1 mole relationship in the balanced equation.

Na₂SO₄ contains two sodium ions per formula unit. Therefore, 0.5 mole gives one mole of Na⁺ ions.

Each formula unit contains three ions. Therefore, one mole contains three times Avogadro's number of ions.

Hydrogen is the limiting reactant because 9 moles are required. Six moles of hydrogen produce four moles of ammonia.

One mole of Fe₂O₃ produces two moles of iron. Two × 55.85 g equals 111.7 g.

Stoichiometric coefficients indicate mole relationships among reactants and products.

Every mole contains the same number of molecules, although the number of atoms differs.

The mole ratio Al:Cl₂ is 2:3. Therefore, 5 moles of aluminium require 7.5 moles of chlorine.

Each mole of sucrose contains 12 moles of carbon atoms. Therefore, two moles contain 24 moles.

Stoichiometric calculations depend entirely upon balanced mole ratios.