Question

the number of moles of h2o which contain 4 g of oxygen

Answer 1

Explanation:

We have oxygen here, okay now oxygen’s atomic mass is 16. That means 16 grams of oxygen is 1 mole of oxygen.

1 mole = 6.022 x 10^23 atoms <== Avogadros’s constant

16G = 1 mole = 6.022 x 10^23 atoms of oxygen

16G = 1 mole ; then 4G = how many moles?

4/16 = 0.25 mole; That means 4 grams of oxygen is 0.25 moles.

So we multiply 0.25 by the no. of atoms in one mole (Avogadro’s constant)

0.25 x (6.022 x 10^23) = 1.5055 x 10^23

Thus 4 grams of oxygen has 1.5055 x 10^23 atoms.

Hope it was helpful :)

Answer 2

Answer:

4/16 = 0.25 mole; That means 4 grams of oxygen is 0.25 moles.