what two ingredients are used to prepare basic buffer solution??
Alkaline buffer solutions
An alkaline buffer solution has a pH greater than 7. Alkaline buffer solutions are commonly made from a weak base and one of its salts.
A frequently used example is a mixture of ammonia solution and ammonium chloride solution. If these were mixed in equal molar proportions, the solution would have a pH of 9.25. Again, it doesn't matter what concentrations you choose as long as they are the same.
Right on the money, BP... If I may add, how about an acidic 50/50 buffer. HOAc/NaOAc (Acetic Acid/Sodium Acetate), Ka=1.8x10^-5... For any 50/50 acidic buffer given the Ka of the weak acid, the buffer pH = pKa = -log(Ka) = -log(1.8x10^-5) = -(-4.74) = 4.74. For any 50/50 alkaline buffer pH = 14 + pKb of weak base. pKb = -log(Kb) For a 50/50 Ammonia/Ammonium Chloride buffer given pKb(NH4OH) = 1.8 x 10^-5 => pH = 14 + (-log(Kb)) = 14 + (-log(1.8x10^-5)) = 14 + (-4.74) = 14 - 4.74 = 9.25... Good job, BP.
To prepare a basic buffer solution, you would typically use a weak base and its conjugate acid. The two ingredients commonly used are a weak base and a salt of its conjugate acid.
Here's how you would prepare a basic buffer solution:
1. Choose a weak base: Examples of weak bases commonly used in buffer solutions are ammonia (NH3) or ammonium hydroxide (NH4OH). For this example, let's use ammonia.
2. Dissolve the weak base: Start by dissolving a certain amount of the weak base (ammonia) in water. The concentration of the weak base will depend on the desired pH of your buffer solution.
3. Choose the conjugate acid salt: The conjugate acid of the weak base is ammonium (NH4+). To prepare the salt, you would typically use ammonium chloride (NH4Cl) or ammonium acetate (NH4CH3COO). These salts are readily available and provide the conjugate acid needed for the buffer solution.
4. Add the conjugate acid salt: Once the weak base is completely dissolved in water, add the salt (ammonium chloride or ammonium acetate) to the solution. The amount of salt to be added depends on the desired concentration and pH of the buffer solution.
5. Mix and adjust pH: Stir the solution to ensure the weak base and its conjugate acid are evenly distributed. At this point, the buffer solution is ready. However, if the pH is not at the desired level, you can adjust it by adding a small amount of acid or base as needed.
It's important to note that the specific amount of weak base and salt required will depend on the desired pH and buffering capacity of the solution. Calculations using the Henderson-Hasselbalch equation can help determine the appropriate amounts of these ingredients.