Question

How many moles of oxygen gas (O2) are in a 2.50 L container at standard temperature and pressure?

Answer 1

Hey there!:

1 mole O2 ----------------- 22.4 L  ( at STP )

( moles O2 ) -------------- 2.50 L

moles O2  = 2.50 * 1 / 22.4

moles O2 = 2.50 / 22.4

moles O2 =  1.12*10⁻¹

Answer B

Hope that helps!