A gaseous mixture of O2 and N2 contains 35.4 % nitrogen by mass. What is the partial pressure of oxygen in the mixture if the total pressure is 0.918 atm

0.565 atm

Explanation:

Let's assume we have 100 g of the gas. We'd then have 35.4 g of N₂ and (100 - 35.4) 64.6 g of O₂.

Now we convert those masses into moles, using their respective molar masses:

Then we calculate the molar fraction of O₂:

Finally we calculate the partial pressure of O₂:

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.