Question

4.The teacher instructed three students A , B, and C respectively to prepare a 505
solution of sodium hydroxide A dissolved 50g of NaOH in 100 ml of water,B
dissolved 50 g of NaOH in 100 g of water while C dissolved 50 g of NaOH in water
to make 100 ml of solution .which one of them has made the desired solution and
why?

Answer 1

The teacher instructed three students A , B, and C respectively to prepare a 505

solution of sodium hydroxide A dissolved 50g of NaOH in 100 ml of water,B

dissolved 50 g of NaOH in 100 g of water while C dissolved 50 g of NaOH in water

to make 100 ml of solution .which one of them has made the desired solution and

why?

Ans

Mass by volume %=Volume of solutionMass of solute×100

=10050×100

=50% mass by volume

50 % Mass by volume means 50g of NaOH is dissolved in 100ml of solution. So C makes the solution. A has taken 100 ml of water itself. Hence, A does not make the desired solution. B has taken 100 gm of water. Thus, for B also, the solution will not be 50% mass by volume.