QUESTION 25
How many H20 molecules are in 24 g H20?

8.03x10^23 molecules.

Explanation:

A background knowledge of Avogadro's hypothesis shows that 1 mole of any substance contains 6.02x10^23 molecules

From the above hypothesis which is know today as Avogadro's law, 1 mole of H2O also contains 6.02x10^23 molecules.

1 mole of H2O = (2x1) + 16 = 2 + 16 = 18g.

Now, we can find the number of molecules contained in 24g of H2O as follow:

18g of H2O contains 6.02x10^23 molecules.

Therefore, 24g of H2O will contain = (24x6.02x10^23)/18 = 8.03x10^23 molecules.

From the calculations made above,

24g of H2O contains 8.03x10^23 molecules.

c. 75.7

i think that is the right