Question

5 The teacher instructed 3 students X, Y and Z to prepare a50% (mass by volume) solution of sodium

hydroxide. X dissolved 50 grams of NaOH in 100 ml of water. Y dissolved 50 grams of NaOH in 100 grams

of water while Z dissolved 50 grams of NaOH in water to make 100 ml solution. Which one of them has

made the desired solution and why?​

Answer 1

Explanation:

ANSWER

'C' has made the desired solution

Mass by volume %=

Volume of solution

Mass of solute

×100

=

100

50

×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.

Answer 2

Explanation:

50 percent mass by volume