Question

calculate the mass of one molecule of water.???​

Answer 1

Answer:

mass of 1 mole of water (H2O) molecule

= 18g.

6.022 x 10²³ molecule of water (H2O) has a mass = 18g.

So...

1 molecule of water (H2O) has a mass

= 18 / 6.022 x 10 ²³

= 2.99 x 10^-23 grams..

Answer 2

The average mass of one H2O molecule is 18.02 amu. The number of atoms is an exact number, the number of mole is an exact number; they do not affect the number of significant figures. The average mass of one mole of H2O is 18.02 grams. This is stated: the molar mass of water is 18.02 g/mol.