Question

Calculate the number of molecules of oxygen gas that occupies a volume of 224 ml at 273 K and 3 atm pressure.

Answer 1

Let say Number of moles of oxygen is n then using ideal gas equation.

PV = nRT

3atm x 0.224L = n x 0.082 x 273 k

n = 0.03 mole

As we know

 ∵ 1 mole oxygen contain = 6.022 x 10²³ oxygen molecule

∴ 0.03 moles oxygen contain  = 0.03 x 6.022 x 10²³

 = 1.81 x 10²² oxygen molecule