Question

the mass of one molecule of water (h2o) is_______.
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Thank You in advance :)​

Answer 1

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.

Answer 2

Heya,

18 g of water contains 6 × 10^23 molecules

Mass of 1 molecule of water = 18 / (6 × 10^-23)

= 3 × 10^-23 grams

HOPE IT HELPS:)