Question

Question 19
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?

Answer 1

In the given question, student 'C' has made it correctly because 50% (mass by volume) means 50 g of solute for every 100 mL of solution and not in 100 mL of solvent.
Student A' dissolved 50 g of NaOH in 100 mL of water (solvent) which is incorrect. Student 'B' dissolved 50 g of NaOH in 100 g of water (solvent), which is incorrect.