🧪 Dilution Calculator

Problem: You have 5 mL of a 10 M stock solution and you dilute it to a final volume of 50 mL. What is the final concentration?

1. Formula: C₂ = (C₁ × V₁) / V₂
2. Values: C₁ = 10 M, V₁ = 5 mL, V₂ = 50 mL
3. Calculation: C₂ = (10 × 5) / 50 = 50 / 50 = 1 M
4. Result: The final concentration is 1 M

Problem: You need to prepare 100 mL of a 0.5 M solution from a 5 M stock solution. How much stock solution do you need?

1. Formula: V₁ = (C₂ × V₂) / C₁
2. Values: C₁ = 5 M, C₂ = 0.5 M, V₂ = 100 mL
3. Calculation: V₁ = (0.5 × 100) / 5 = 50 / 5 = 10 mL
4. Result: You need 10 mL of stock solution, then add diluent to 100 mL total

Problem: Perform an 8-step 2-fold serial dilution starting from a 1 mM stock solution.

1. Formula: C_n = C_stock / 2ⁿ
2. Step 1: C₁ = 1 mM / 2 = 0.5 mM (500 μM)
3. Step 2: C₂ = 1 mM / 4 = 0.25 mM (250 μM)
4. Step 3: C₃ = 1 mM / 8 = 0.125 mM (125 μM)
5. Step 4: C₄ = 1 mM / 16 = 0.0625 mM (62.5 μM)
6. Step 5: C₅ = 1 mM / 32 = 0.03125 mM (31.25 μM)
7. Step 6: C₆ = 1 mM / 64 = 0.015625 mM (15.625 μM)
8. Step 7: C₇ = 1 mM / 128 = 0.0078125 mM (7.813 μM)
9. Step 8: C₈ = 1 mM / 256 = 0.00390625 mM (3.906 μM)

Problem: You have a 50 μM stock solution of a drug. You need to prepare 200 μL of a 5 μM working solution. How much stock and how much diluent?

1. Formula: V₁ = (C₂ × V₂) / C₁
2. Values: C₁ = 50 μM, C₂ = 5 μM, V₂ = 200 μL
3. Stock needed: V₁ = (5 × 200) / 50 = 20 μL
4. Diluent needed: V₂ - V₁ = 200 - 20 = 180 μL
5. Result: Mix 20 μL of stock with 180 μL of diluent