Question

How many moles are in 68.5 liters of oxygen gas at STP?

Answer 1

It is a given that the molar volume of an ideal gas at STP is `22.414` `L*mol^-1`. This would probably even appear on a test paper as supplementary info.

Explanation:

So to get the molar quantity, we simply divide the actual volume by the molar volume:

`(68.5*cancelL)/(22.414*cancelL*mol^-1)` `=` `"approx. "3*mol`.