Question

1. explain how you would make 100 mL of a 2.0% (w/v) solution of sodium chloride?

2.How many grams of magnesium sulfate are required to make 250 mL of a 1.6% MgSO4 (m/v) solution?

3. A solution contains 2.7 g of CuSO4 in 75 mL of solution. What is the percent (mass/volume) of the solution

Answer 1

1. Percent (mass/volume) of the solution = (mass of the solute / volume of the solution) × 100

Given, percent of NaCl (m/v) solution = 2.0 %

Volume of solution = 100 ml

By putting the values we get,

2.0 = (mass of NaCl / 100) × 100

Mass of NaCl = (2.0 × 100) / 100 = 2 g

So, there is a need to dissolve 2 grams of NaCl in 100 ml water to produce 2.0 % NaCl solution.

2. Percent (mass / volume) of the solution = (mass of the solute / volume of the solution) × 100

Given, percent of MgSO₄ (m/v) solution = 1.6 %

Volume of the solution = 250 ml

By putting the values we get,

1.6 = (mass of MgSO₄ / 250) × 100

Mass of MgSO₄ = (1.6 × 250) / 100 = 4 g

3. Percent (mass/volume) of the solution = (mass of the solute / volume of the solution) × 100

Given, mass of CuSO₄ = 2.7 g

Volume of solution = 75 ml

Percent (mass / volume) of the solution = (2.7 g / 75 ml) × 100 = 3.6 %