Question

Calculate no of moles of hydrogen atoms in 45g of water

Answer 1

Moles of water=45/18.
no of H atoms in a water molecule =2.
moles of H atoms in 1 mol water molecule=2 mole.
moles of H atoms in 45/18 mole of water= 2×(45/18) moles.
Hence number of H atoms in 45g of water = 2×(45/18)×N.
(where N is Avogadro's number.)

Answer 2

Answer:

Moles of water = 45/18

no of H atoms in a water molecule =2.

moles of H atoms in 1 mol water molecule=2 mole. 

moles of H atoms in 45/18 mole of water= 2×(45/18) moles.

Hence number of H atoms in 45g of water = 2×(45/18)×N