Question

calculate the molarity of pure water, density of water is 1gml

Answer 1

Molarity is defined as the number of moles of the solute per litre of solution

Molarity = Number of moles of solute / Volume of solution (in litres)

We are given that density of water is 1 g/ ml. This is equal to 1 Kg/ L. Therefore mass of 1 Litre of water will be

= density of water X Volume ( using the relation density = mass / volume)

= 1 Kg / L X 1 L

= 1Kg = 1000 g

Therefore number of moles in 1Kg of water = mass / molar mass = 1000 / 18 = 55.56

Therefore molarity of water = 55.56 / 1 Litre =55.56 moles / L