hello rohit

As we know that for a molecule, molecular weight in grams is equal to the Avogadro number and for transforming between moles and grams, we could use the molar mass of the substance. Avogadro’s number can be expressed as the number of elementary particles such as molecules, atoms, compounds, etc. per mole of a substance and Avogadro number is often denoted as NA.

18 mole of water will contain 18×6.023×1023 number of molecules.

therefore the number of water molecules is maximum in 18 moles of water.

hope this will help you a  lot.

thank you.

Hello candidate,

The above question mentioned seems to be taking update of information because you have not clearly mentioned the compound or the element in which you want to count the number of water molecules.

It's better if you just go through your question again and repost it with correct set of information.

Feel free to ask other queries!!