Atomic mass. Which is the number of protons and neutrons combined.
Answer: The partial pressure of oxygen in the mixture if the total pressure is 525 mmHg is 310 mm Hg
Explanation:
mass of nitrogen = 37.8 g
mass of oxygen = (100-37.8) g = 62.2 g
Using the equation given by Raoult's law, we get:

= partial pressure of
= ?

= total pressure of mixture = 525 mmHg


Total moles = 1.94 + 1.35 = 3.29 moles


Thus the partial pressure of oxygen in the mixture if the total pressure is 525 mmHg is 310 mm Hg