Question

a) to make 1000 g of a 10% (by mass. m/m%) aqueous glucose solution one must dissolve \boxed{} g glucose in \boxed{} g of water. b) to make 750 g of a 16% (by mass, m/m%) aqueous sodium chloride solution, one must dissolve \boxed{} g of sodium chloride in \boxed{} g of water. c) to make 550 ml of a 12% (by volume, v/v%) aqueous ethylene glycol solution, one must measure out \boxed{} ml of ethylene glycol and add enough water to make \boxed{} ml of the solution.

Explanation:

Part (a)

Step1: Calculate mass of glucose

Mass percentage formula: $m/m\%=\frac{\text{mass of solute}}{\text{mass of solution}}\times100\%$. For 10% (m/m) solution, mass of solution = 1000 g. So, mass of glucose = $0.10\times1000 = 100$ g.

Step2: Calculate mass of water

Mass of water = mass of solution - mass of solute = $1000 - 100 = 900$ g.

Step1: Calculate mass of NaCl

Using $m/m\%=\frac{\text{mass of solute}}{\text{mass of solution}}\times100\%$. For 16% (m/m) solution, mass of solution = 750 g. Mass of NaCl = $0.16\times750 = 120$ g.

Step2: Calculate mass of water

Mass of water = $750 - 120 = 630$ g.

Step1: Calculate volume of ethylene glycol

Volume percentage formula: $v/v\%=\frac{\text{volume of solute}}{\text{volume of solution}}\times100\%$. For 12% (v/v) solution, volume of solution = 550 mL. Volume of ethylene glycol = $0.12\times550 = 66$ mL.

Step2: Volume of solution

The final volume of solution is given as 550 mL (we add water to make this volume).

Answer:

100 g glucose in 900 g water.

Part (b)