Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain.Calculate the mass in grams of 3.65 × 10²⁰ molecules of sulfur trioxide.

Question

Quizplus · Accepted Answer

First, we need to calculate the molar mass of sulfur trioxide:

S = 32.07 g/mol 
O = 16.00 g/mol

Molar mass of SO3 = (1 × 32.07) + (3 × 16.00) = 80.07 g/mol

Next, we can use dimensional analysis to convert from molecules to grams:

3.65 × 10^21 molecules SO3 × (1 mol SO3/6.022 × 10^23 molecules SO3) × (80.07 g SO3/1 mol SO3) = 4.85 × 10^-12 g SO3

Therefore, the mass of 3.65 × 10^21 molecules of SO3 is 4.85 × 10^-12 g, which is closest to choice C.

Sulfur Trioxide Can React with Atmospheric Water Vapor to Form