Question

The teacher instructed three students A, b and C respectively to prepare a 50% (mass by volume) solution of NaOH. Student A dissolved %50g of NAOH in 100 mL of water. Student B dissolved 50 g of NAOH in 100g of water. Student C dissolved 50g of NAOH in water to make 100 mL of solution. which one of them has made the desired solution and WHY?

Answer 1

student A and B make solution about 150 ml so,
student c make desire solution bcoz he add water to make 100 ml solution.
and from calculation,
%w/v = 100 × weight of sub (solute)
                 volume of solution

∴ %50 = 100 × weight of sub
                    100 ml

   weight of sub = 50 ×100 ml
                               100

∴  weight of sub = 50 g

here the 50g NaOH requred for 50% w/v 100ml solution of NaOH

Answer 2

Here is your answer mate