how many moles are present in 9g of water
Water(H2O) has a molecuar mass of 18, this means it weights 18 g per mole. A mole is 6.0221415*1023molecules (Avogadro's number). If you have 1 g of water, you therefore have 1/18 of a mole, or 3.34*1022 molecules.
and in 9 gm of water you have 9/18 of mole or 3.011*1023 molecules