Question

Calculate the mass of 12.044 ×10^25 molecules of oxygen (o2)

Answer 1

 easily, 1 mol = 6(,023) x 10^23 atoms.

So, there’s 12 x 10^23 atoms of Oxygen, hence there’s 2 moles of Oxygen.

There’s an equation : m (mass of substance) = n (substance’s mol) x M (substance’s molar mass)

Now, what we need here is to identify “m” (mass).

n = 2 (as calculating above), M of Oxygen is 16

So that, m = 2 x 16 = 32 (g)

Concluding, 12 x 10^23 atoms of Oxygen is heavy as 32 (g)