Question

A sample of air contains 78.08% Nitrogen, 20.94% oxygen and 0.980% Argon, by volume. How many moles of oxygen are present in 1.00L of the sample at 25.0 ^oC at 1.00 atm?

Note: if your answer is in exponential form just like this: 5.555 x 10^-7, 

express your answer in this form: 5.555E-7

Answer 1

1.00L = 1000ml = 1000g

20.94/100 × 1000

= 209.4g

Molar Mass of Oxygen = 15.999

= 209.4/15.999

= 13.088 moles