Question

how+many+water+molecules+are+present+in+18+gram+of+water?

Answer 1

formula : number of molecules = given mass / molar mass *avogadro number

so = 18/18*6.022*10^23

    = 6.022*10^23

    = 1  molecule  of water (ans)

     

Answer 2

Number of atoms/molecules :

number of moles of that atom/molecule * Avogadro number

Here number of moles of water :

given molecular mass/molar mass = 18/18 = 1

So number of water molecules = 1 * Avogadro number

i.e 1 * 6.022 × 10^23 = 6.022 * 10^23

Answer = 6.022 * 10^23 molecules are there of water in 18 g of water.