Answer: 2.9 x 10^23 atoms
Explanation:
First get the molar mass of water, H2O
(1x2) + 16 = 18g
Recall that based on Avogadro's law, 1 mole of any substance has 6.02 x 10^23 atoms
So if 1 mole of H2O has a molar mass of 18g We can say 18g = 6.02 x 10^23 atoms
Then, 18g = 6.02 x 10^23 atoms
8.65g = Z atoms
To get the value of Z, we cross multiply:
18g x Z atoms= (6.02 x 10^23 atoms) x 8.65g
18Z = 52.07 x 10^23 atoms
Hence, Z = (52.07 x 10^23 atoms) ➗ 18
Z = 2.9 x 10^23 atoms
Thus, there are 2.9 x 10^23 atoms in 8.65 g of H2O
