You are here
Student A dissolves 20 g sugar in 80 g water; Student B dissolves 20 g sugar in 100 g water; Student C dissolves 30 g sugar in 80 g water. (i) Calculate the % m/m of each. (ii) Whose solution is most concentrated? Explain.
View Answer
(i) Using % m/m = \( \dfrac{\text{mass of sugar}}{\text{mass of solution}}\times100 \):
A = \( \dfrac{20}{100}\times100 = 20\% \); B = \( \dfrac{20}{120}\times100 = 16.7\% \); C = \( \dfrac{30}{110}\times100 = 27.3\% \).
(ii) Student C's solution is the most concentrated (27.3%), because it has the most sugar in the least amount of solution.
← Back to concept: 5.2.2 Expressing concentration