When 100 grams of He and 100 grams Ne are placed in a container, the partial pressure of Ne is found to be 3 atm. What is the partial pressure of He?

Question

When 100 grams of He and 100 grams Ne are placed in a container, the partial pressure of Ne is found to be 3 atm. What is the partial pressure of He?

The answer is 15 atm. Can someone please explain why that is and show the steps on how to get 15 atm?

Answer 1

100 g He x (1 mole He/4.00 g He) = 25 moles of He

100 g Ne x (1 mole Ne/20.18 g He) = 4.96 moles of Ne, call it 5!!!

3 atm/ 5 moles = x atm/25 moles

x = 15 atm.

Concepts: using molar mass to convert from grams to moles, understanding that pressure is caused by the number of particles colliding with the walls of a container, setting up a ratio because pressure is defined by number of particles per volume