Question

180gms of water contains how many moles?
(with full solution).

Answer 1

no. of moles- mass/atomic mass so
no. of moles in 180 gms water-180/18=10 moles

Answer 2

Let no. of moles in 180g of H2O be x.

1 mole of H2O = 18g of H2O

x moles of H2O = 180g of H2O

⛬No. of moles = 18x = 180

x = $\dfrac{180}{18}$

x = 10

Alternative method,

No. of moles = $\dfrac{given \ weight}{molar\:mass}$

= $\cancel\dfrac{180}{18}$

=10