LAS 4 - Concentration of Solution

Calculate the concentration of a solution (in percent) of 9.0 g of salt in 100.0 g of solution

• 9% salt

• 9 g salt

• 90% salt

• 90 g salt

A sample of 0.892 g of potassium chloride is dissolved in 54.6 g of water. What is the percent by mass of KCl in the solution?

• 16.1% KCl

• 161% KCl

• 1.61% KCl

• 0.161% KCl

What is the percentage by mass of a solution made by dissolving 12.0 g salt in 250 mL water? (Density of water= 1.0 g/mL)

• 54.8% salt

• 5.48% salt

• 45.8% salt

• 4.58% salt

A 40.0-gram sample of methanol, CH₄O is mixed with 60.0 grams of ethanol, C₂H₆O. What is the mole fraction of the methanol?

• 0.49

• 0.54

• 0.65

• 0.72

Hydrogen peroxide, H₂O₂, is used by some water treatment systems to remove the disagreeable odor of sulfides in drinking water. An aqueous solution of H₂O₂ prepared in the laboratory was found to have a concentration of 20.0% by mass. What is the mole fraction of H₂O₂?

• 0.921

• 0.546

• 0.117

• 0.324

To prevent dehydration, intravenous (IV) solution is given to hospital patients. Commonly used are solutions containing sodium chloride and glucose. A 150.0 mL IV solution contains 6.60 grams glucose (C₆H₁₂O₆). What is the molarity of this solution? The molar mass of glucose is 180.16 g/mol.

• 0.623 M

• 0.244 M

• 0.513 M

• 0.913 M

3.0 moles of NaCl is dissolved in 2000 g of water. Solve for the molality.

• 2.5 m

• 3.5 m

• 1.5 m

• 4.5 m

What mass of nitric acid, HNO₃ is present in 5000 mL, 1.24 molar solution?

• 190.60 g HNO3

• 290.60 g HNO3

• 390.60 g HNO3

• 490.60 g HNO3

Calculate the molarity of a solution made by dissolving 23.4 g of sodium sulfate, Na₂SO₄, in enough water to form 125 mL of solution.

• 0.32 M

• 1.32 M

• 2.32 M

• 3.32 M

How many grams of Na₂SO₄ are required to make 0.350 L of 0.500 M Na₂SO₄

• 2.49 g Na₂SO₄

• 24.9 g Na₂SO₄

• 249 g Na₂SO₄

• 2490 g Na₂SO₄