Question

Which of the following compounds contains the SMALLEST percent oxygen by mass?

A) P₄O₁₀
B) N₂O₄
C) CO₂
D) SO₂

Answer 1

After calculating the percent composition of oxygen in each compound, SO2 is found to have the smallest percent oxygen by mass at 49.9%.

Step-by-step explanation:

To determine which of the following compounds contains the SMALLEST percent oxygen by mass, we must calculate the percent composition of oxygen in each compound.

• P4O10 - Molecular weight: 283.9 g/mol (P: 123.9 g/mol, O: 160.0 g/mol). Percent oxygen = (160.0/283.9) * 100 = 56.4%.
• N2O4 - Molecular weight: 92.02 g/mol (N: 28.02 g/mol, O: 64.0 g/mol). Percent oxygen = (64.0/92.02) * 100 = 69.5%.
• CO2 - Molecular weight: 44.01 g/mol (C: 12.01 g/mol, O: 32.0 g/mol). Percent oxygen = (32.0/44.01) * 100 = 72.7%.
• SO2 - Molecular weight: 64.07 g/mol (S: 32.07 g/mol, O: 32.0 g/mol). Percent oxygen = (32.0/64.07) * 100 = 49.9%.

Comparing the percentages, SO2 contains the smallest percent oxygen by mass at 49.9%.