Question

1. An aqueous solution of potassium thiosulfate is prepared by dissolving 3.70 g of potassium thiosulfate in 7.11×10² g of water. The density of the solution is 1.37 g mL^-1.


a) Determine the mass percent of potassium thiosulfate in the solution.

b) Determine the mole fraction of potassium thiosulfate in the solution.

2. An aqueous solution of potassium bromide is prepared by dissolving 8.75 g of potassium bromide in 8.29×10² g of water. The density of the solution is 1.20 g mL^-1.

Determine the molarity (in mol/L) of potassium bromide in the solution.

Answer 1

An aqueous solution of potassium thiosulfate is prepared by dissolving 3.70 g of potassium thiosulfate in 7.11x102 g of water. The density of the solution is 1.37 g mL-1. Determine the mass percent of potassium thiosulfate in the solution. Determine the mole fraction of potassium thiosulfate in the solution. An aqueous solution of potassium bromide is prepared by dissolving 8.75 g of potassium bromide in 8.29 times 102 g of water. The density of the solution is 1.20 g mL-1. Determine the molarlty (in mol'L) of potassium bromide in the solution. K_2 O_3 S_2 (potassium thiosulfate) more = 2 times 39 + 3 + 16 + 2 times 32 = 78 + 48 + 64 190 gl mol H_2 O rightarrow molar mass = 18 gl mol mass present of potasium thiosulfate = g of potasium thiosulfate/g of k_2 o_3 s_2 + g of water times 100 = 3.70/3.70+7.11 times 10^2 3.70/3.70+7.11 times 100