Molarity and Dilution Practice

Molarity and Dilution Practice

Read each question carefully and provide the best answer. Show all your work for calculations.

1. Calculate the molarity of a solution prepared by dissolving 25.0 g of NaCl in enough water to make 500.0 mL of solution. (Molar mass of NaCl = 58.44 g/mol)

2. How many grams of potassium iodide (KI) are needed to prepare 2.5 L of a 0.75 M solution? (Molar mass of KI = 166.00 g/mol)

3. Molarity is defined as the number of   of solute per liter of  .

4. When diluting a solution, the number of moles of solute  , while the volume of the solution  .

5. Which of the following equations is used for dilution calculations?

6. If you have 100.0 mL of a 2.0 M stock solution of HCl, how much water do you need to add to dilute it to a 0.50 M solution?

7. A chemist wants to prepare 250.0 mL of a 0.15 M NaOH solution from a 6.0 M stock solution. What volume of the stock solution is needed?

8. Adding more solvent to a solution increases its molarity.

9. The total number of moles of solute remains constant during a dilution.