Question

Which of the following statements correctly describe molarity (m) and the process of concentrating or diluting solutions? A) Molarity (M) measures the total volume of a solution, not its concentration. B) The process of concentrating solutions involves adding more solvent, increasing the total volume. C) Diluting solutions involves increasing the amount of solute, making it more concentrated. D) Molarity (M) is a measure of the mass of solute in a solution, not its concentration.

Answer 1

None of the given options accurately describe molarity or the processes of concentrating and diluting solutions. Molarity is a measure of the number of moles of solute per liter of solution, and concentrating a solution involves increasing solute or decreasing solvent. Dilution decreases concentration by adding solvent, and this relationship is described mathematically by the dilution equation M1V1=M2V2.

Step-by-step explanation:

The correct description of molarity (M) and the process of concentrating or diluting solutions among the given options is none, because each statement contains an inaccurate description:

• Molarity (M) measures the total volume of a solution, not its concentration. - This is incorrect because molarity is a measure of concentration, specifically the number of moles of solute per liter of solution.
• The process of concentrating solutions involves adding more solvent, increasing the total volume. - This is incorrect; concentrating a solution involves increasing the solute or decreasing the solvent, which increases concentration without necessarily increasing volume.
• Diluting solutions involves increasing the amount of solute, making it more concentrated. - This is incorrect; diluting a solution involves adding more solvent, thus reducing the concentration of solute.
• Molarity (M) is a measure of the mass of solute in a solution, not its concentration. - This is incorrect; molarity does involve concentration and it is defined as the number of moles of solute per liter of solution.

Molarity (M) is indeed a quantitative measure of solution concentration, representing the number of moles of solute per liter of solution. When a solution is diluted by adding more solvent, the amount of solute remains constant while the total volume of the solution increases. Therefore, the concentration, or molarity, decreases as the total volume increases.

The mathematically derived dilution equation shows the relationship between the initial and final concentrations and volumes: n = M x V, which allows the calculation of the new concentration after dilution, using the equation M1V1=M2V2.

Answer 2

The correct statement about molarity (M) and concentrating/diluting solutions is: D) Molarity (M) is a measure of the number of moles of solute per liter of solution.

A) Molarity (M) measures the total volume of a solution, not its concentration. This is incorrect. Molarity actually measures the concentration of a solution, specifically the number of moles of solute per liter of solution.

B) The process of concentrating solutions involves adding more solvent, increasing the total volume. This is incorrect. Concentrating a solution involves removing solvent, decreasing the total volume and increasing the concentration of the solute.

C) Diluting solutions involves increasing the amount of solute, making it more concentrated. This is incorrect. Diluting a solution involves adding solvent, increasing the total volume and decreasing the concentration of the solute.

Therefore, the only statement that correctly describes molarity and the processes of concentrating/diluting solutions is D.