Answer:
23.6 moles
Explanation:
From the question given above, the following data were obtained:
Mass of air = 3.6 Kg
Mass percentage of Oâ‚‚ = 21%
Number of mole of Oâ‚‚ =?
Next, we shall convert 3.6 Kg of air to grams (g). This can be obtained as follow:
1 kg = 1000 g
Therefore,
3.6 Kg = 3.6 Kg × 1000 / 1 kg
3.6 Kg = 3600 g
Next, we shall determine the mass of Oâ‚‚ in the air. This can be obtained as follow:
Mass of air = 3600 g
Mass percentage of Oâ‚‚ = 21%
Mass of Oâ‚‚ =?
Mass of O₂ = 21% × 3600
Mass of O₂ = 21/100 × 3600
Mass of Oâ‚‚ = 756 g
Finally, we shall determine the number of mole of Oâ‚‚ in the sample of air. This can be obtained as follow:
Mass of Oâ‚‚ = 756 g
Molar mass of O₂ = 2 × 16 = 32 g/mol
Number of mole of Oâ‚‚ =?
Mole = mass /Molar mass
Number of mole of Oâ‚‚ = 756 / 32
Number of mole of Oâ‚‚ = 23.6 moles
Thus, the number of mole of Oâ‚‚ in the
sample of air is 23.6 moles
