Answer to Question #193632 in Chemistry for Valentina

Question

Oxygen is produced by plants during photosynthesis and used by plants and animals for respiration. Predict the chemical amount of oxygen in 12.0L of air at TAPN. Suppose the air is 20% oxygen.

Answer 1

Since the air is 20% oxygen, 12.0 L contain:

V(oxygen) = 12.0 L × 20% / 100% = 2.4 L

As 1 mole of gas occupies 22.4 L, the chemical amount of oxygen equals:

n(oxygen) = 2.4 L × 1 mol / 22.4 L = 0.107 mol

Answer: 0.107 mol