Question

You sealed an Erlenmeyer flask that was determined to have a volume of 272.2 mL with a stopper. The density of air at 25°C is 0.001185 g/mL. Air has an effective molar mass of 28.96 g/mol. What amount of air was sealed in the flask?

Answer 1

Answer:

The amount of air is 11.1 mmol

Explanation:

Density shows the relation between mass and volume, so you can know the mass which has been sealed in the Erlenmayer.

Density = mass/ volume

Density . volume = mass

0.001185 g/ml . 272.2 ml = 0.322 g

We have the mass now, so the molar weight determinates the mols

Mass/molar weight = mol

0.322g/ 28.96 g/m = 0.0111 mol

To get a better number we can inform on milimols

Mols . 1000 = milimols