Question

what is the mass of 0.2 moles of oxygen molecules........

Answer 1

Mass of 1 mole of oxygen = 16 u

Mass of 0.2 moles = 16 * 0.2 = 3.2

Answer 2

n = given mass / molecular mass . n=0.2 molecular mass= 16 g . Therefore , 0.2= mass/16 . Mass = 0.2 into 16 = 3.2-g