The teacher instructed three students 'A', 'B' and 'C' respectively to prepare a `50%` (mass by volume) solution of sodium hydroxide (NaOH). 'A' dissolved 50g of NaoH in 100 mL of water. 'B' dissolved 50g of NaOH in 100g of water while 'C' dissolved 50g of NaOH in water to make 100 mL of solution. Which one of them has made the desired solution and why?

Explanation

The student 'C' has prepared the desired solution since it represents mass/volume solution. The student 'A' has taken into account volume of the solvent while the student 'B' has considered the mass of the solution mass by volume % = `("Mass of solute")/("Volume of solution") xx 100 = (50)/(100) xx 100 = 50%` mass by volume.