How many moles of oxygen are in a 7.68l container at 355k and exerting a pressure of 8.57atm on the walls of the container

We can use the Ideal Gas Law for this question:

So we need to solve the equation for n, the number of moles:

Now we can plug in the values that we are given to solve for the number of moles:

So now we know that there are 2.26 moles of oxygen in the container.

Explanation:

It is given that volume is 7.68 L, temperature is 355 k and pressure is 8.57 atm. So, according to ideal gas equation PV = nRT.

Also, it is known that number of moles equal mass divided by molar mass.

Therefore, putting the given values into the ideal gas equation as follows.

                      PV = nRT

    =

                             n = 2.26 mol

Thus, we can conclude that the number of moles present in given oxygen is 2.26 mol.