Question

The density of water is 1.00 g/ml at 4°c. how many water molecules are present in 2.36 ml of water at this temperature?

Answer 1

Mass of 1 ml of water 1 g as density of water 1.00 g/ml at 4° C. So, mass of 2.36 ml of water $\frac{1}{2.36}$ g= 0.423 g.

Molecular mass of water is 18 g which indicates 18 g water contains 6.023 X $10^{23}$ number of water molecules. So, 0.423 g of water contains $\frac{6.023 X 10^{23} X 0.423 }{18} g$ = 0.141 X $10^{23}$ number of water molecules= 1.41 X $10^{22}$ number of water molecules.