Answer to Question #286859 in General Chemistry for Val

Question

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

Expressed in scientific notation, the chemical amount is a, bc x 10-d mol.

The values ​​of a, b, c and d are respectively..?

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