AP Chemistry solution dilution questions and answers.

🧪 Quick Study Guide

• ⚗️ Dilution is the process of reducing the concentration of a solution by adding more solvent.
• 🔢 The key formula for dilution calculations is: $M_1V_1 = M_2V_2$, where:
  • $M_1$ = Initial concentration (Molarity)
  • $V_1$ = Initial volume
  • $M_2$ = Final concentration (Molarity)
  • $V_2$ = Final volume
• 💧 Remember that volume units must be consistent (e.g., both in mL or both in L).
• 🧮 When solving dilution problems, identify the knowns and unknowns, then rearrange the formula to solve for the desired variable.
• 💡 Always double-check your units and make sure your answer makes sense in the context of the problem. A smaller concentration should result from a larger final volume, etc.

🤔 Practice Quiz

1. What is the final concentration when 50.0 mL of a 2.0 M solution of NaCl is diluted to 250.0 mL?
   1. 0.1 M
   2. 0.4 M
   3. 2.0 M
   4. 10.0 M
2. If you have 100 mL of a 0.5 M solution of HCl, how much water must be added to dilute it to 0.1 M?
   1. 100 mL
   2. 400 mL
   3. 500 mL
   4. 600 mL
3. What is the initial volume needed to prepare 500.0 mL of a 0.250 M solution from a 1.00 M stock solution?
   1. 100.0 mL
   2. 125.0 mL
   3. 200.0 mL
   4. 250.0 mL
4. A student needs to prepare 250 mL of a 0.10 M solution of $CuSO_4$ from a 1.0 M stock solution. What volume of the stock solution is required?
   1. 2.5 mL
   2. 25 mL
   3. 50 mL
   4. 100 mL
5. What is the molarity of a solution prepared by diluting 25.0 mL of a 3.0 M $HNO_3$ solution to a final volume of 500.0 mL?
   1. 0.075 M
   2. 0.15 M
   3. 0.30 M
   4. 0.60 M
6. You dilute 20.0 mL of a 5.0 M solution to a final volume of 1.0 L. What is the new concentration?
   1. 0.01 M
   2. 0.1 M
   3. 1.0 M
   4. 2.5 M
7. If 200 mL of water are added to 300 mL of 2.0 M solution, what is the resulting molarity?
   1. 0.8 M
   2. 1.2 M
   3. 1.6 M
   4. 2.0 M