Question

A solution of table sugar in water contains 5.25% by mass sucrose. Calculate

A. The mass of sucrose in 225 g of solution

B. The amount of solution needed to obtain 70.0 g of sucrose.

C. The mass of water contained in 450 g of the solution

D. The mole fraction of sucrose and water in 5.25% by mass sucrose.

Answer 1

a. 5.25% of 225g = 11.813g

b. 5.25% = 70.0g

100% = x

x = (100% × 70.0) / (5.25%)

= 1333.3g

c. water = 100% - 5.25% = 94.75%

94.75% of 450g = 426.375g

d. mole fraction = number of moles of solute/ number of moles of solute + solvent

= (5.25/342.3) / (5.25/342.3 + 95.75/18)

= 0.0287