Question

what is mole concept? calculate the number of molecules in 45g of water

Answer 1

mole is defined as the ratio of given wt to the molecular wt
no. of molecules= (45/34)*6.022×10^23

Answer 2

Mole concept: Mole can be defined as the amount of a substance , which contains the same number of chemical units (atoms, molecules ,ionsor electrons) as there are atoms in exactly 12 grams of pure carbon 12.
A mole represents a collectio of
$6.022\times 10 {}^{23}$
(avagardro number) chemical units.

No. of molecules = 45÷34×6.022×10^23