Question

Map Sapling Learning Dry air (0% humidity) is approximately 78% N2, 21% O2, and 1% Ar by moles. Calculate the molar mass and density of dry air at 0 °C and 1.0 atm. Assume ideal behavior and use two significant figures in your answers Number Number g/ mol molar mass density Typical outdoor air also has water vapor, H20 (g), mixed in with the other gases. Consider the molar mass and density of humid air compared to dry air E the molar mass of dry air The molar mass of humid air is Select answer The density of humid air is Select answer the density of dry air. greater than equal to less than O Previous Next Check Answer Give Up & View Solution

Answer 1

Answer:

The density is 1.3 g/L

Explanation:

Step 1: Data given

Dry air contains 78% N2, 21% O2 and 1% Ar

Molar mass N2 = 28 g/mol

Molar mass O2 = 32 g/mol

Molar mass Ar = 39.95 g/mol

Step 2: Calculate molar mass

Molar mass = 0.78 * 28 + 0.21*32 + 0.01 * 39.95

Molar mass = 28.96 g/mol

Step 3: Calculate the density

At STP Molar volume is  22.4 mol/L

Density = molar mass / molar volume

Density = 28.96 / 22.4

Density = 1.3 g/L

The density is 1.3 g/L