Question

Calculate the mass percent, % (m/m), for the solute in each of the following solutions.

Part A

24 g of KCl and 100 g of H2O

Express your answer using two significant figures.

Part B

11 g of sugar in 200 g of tea with sugar (solution)

Express your answer using two significant figures.

Part C

6.0 g of CaCl2 in 65.0 g of CaCl2 solution

Express your answer using two significant figures.

Answer 1

solution mass = solute mass + solvent mass , hence for part A solution mass is 24+100 = 124 g , similarly for B solution mass is 211 g , for part C solution mass is 65+6 = 71 g

A) mass % of KCl =( 100 x KCl mass) / ( solution mass)

                  = ( 100 x 24 ) / ( 124) = 19 %

B)   mass %% of sugar = ( 100 x 11 /211) = 5.2 %

C) CaCl2 % = ( 100 x 6 /71) = 8.5 %