Larutan buffer, pembuatan larutan buffer.pptx

Pembuatan larutan buffer

1. LULU’ATUL HAMIDATU ULYA, M.Sc. BUFFER SOLUTION ORGANIC CHEMISTRY-BIOLOGY DEPARTMENT UIN MAULANA MALIK IBRAHIM MALANG.

2. BUFFER SOLUTION 01 Buffer solution What is buffer solution and it’s component? 02 Preparing a buffer solution with a specific pH H o w to prepare a buffer solution with a specific pH? 03 Example of buffer solution What are examples of buffer solution? 04 Practice exercise How to practice of making buffer solution?

3. A buffer solution is a solution of (1) a weak acid or a weak base and (2) its salt; both components must be present. The solution has the ability to resist changes in pH upon the addition of small amounts of either acid or base BUFFER SOLUTION

4. A solution containing these two substances has the ability to neutralize either added acid or added base. —BUFFER SOLUTION

5. Sodium acetate, a strong electrolyte, dissociates completely in water. Strong electrolyte BASE WILL BE NEUTRALIZED BY ACID Conjugate base If an acid is added, the H + ions will be consumed by the conjugate base in the buffer, CH 3 COO - If a base is added to the buffer system, the OH - ions will be neutralized by the acid in the buffer EXAMPLE OF BUFFER SOLUTION (CH 3 COOH + CH 3 COONa)

6. CH 3 COOH + CH 3 COONa (buffer solution) CH 3 COOH + CH 3 COONa (buffer solution) added by HCl EXAMPLE OF BUFFER SOLUTION BUFFER SOLUTION NOT BUFFER SOLUTION (a) and (b) (c) and (d) (c) CH 3 COOH (d) CH 3 COOH added by HCl *Notes: Using bromophenol blue indicator

7. EXAMPLE OF BUFFER 1. Which of the following solutions can be classified as buffer systems? (a) KH 2 PO 4 /H 3 PO 4 (b) NaClO 4 /HClO 4 2. Calculate the pH of a buffer system containing 1 M CH 3 COOH and 1 M CH 3 COONa. Ka of CH 3 COOH is 1,8 x 10 -5 . CH 3 COOH ( aq ) → H+ ( aq ) + CH 3 COO- ( aq )

8. PREPARING A BUFFER WITH A SPECIFIC pH

9. PREPARING A BUFFER WITH A SPECIFIC pH Describe how you would prepare a “phosphate buffer” with a pH of about 7.45 So, the way to prepare a phosphate buffer with a pH of 7.45 is to dissolve disodium hydrogen phosphate (Na 2 HPO 4 ) and sodium dihydrogen phosphate (NaH 2 PO 4 ) in a mole ratio of 1.7:1.0 in water.

10. EXERCISE Which of the following are buffer systems? KF/HF, KBr / HBr , Na 2 CO 3 /NaHCO 3 2. Calculate the pH of the 0.30 M NH3/0.36 M NH4Cl buffer system,Kb = 10 -5 3. How would you prepare a liter of “carbonate buffer” at a pH of 10.10? You are provided with carbonic acid (H 2 CO 3 ), sodium hydrogen carbonate (NaHCO 3 ), and sodium carbonate (Na 2 CO 3 )

11. THANKS Does anyone have any questions? [email protected] [phone]