Question

how many moles is equal to half litre of water

Answer 1

We know,

The density of water = 1 Kg/ L.

Therefore, mass of 1 litre of water = density of water x Volume (since, density = M / V)

= 1 Kg / L x 1 L

= 1Kg

= 1000 g

Thus the mass of ½ litre of water = 1000 x ½ = 500g

Hence, the number of moles in 500g of water = mass / molar mass

= 500 / 18

= 27.77