Consider a 1L, 200mm acetate buffer with pH = 6.0 and with a pKa of 4.73...
1) Suppose you have 50ml of a 0.1M acetate buffer with a pH of 4.37 and a pka of 4.73 which has been treated with 2.4 ml of 0.5M Sodium Hydroxide (NaOH). Calculate the theoretical change in pH following the addition of this base.
What concentrations of acetic acid (pKa 4.76) and acetate would be required to prepare a 0.10 M buffer solution at pH 4.5? Note that the concentration and/or pH value may differ from that in the first question. STRATEGY 1. Rearrange the Henderson-Hasselbalch equation to solve for the ratio of base (acetate) to acid (acetic 2. Use the mole fraction of acetate to calculate the concentration of acetate. 3. Calculate the concentration of acetic acid Step 1: Rearrange the Henderson Hasselbalch...
Henderson-Hasselbach equation: pH- pKa log (IA-|/IHA]) 1. Phosphate buffer is a mixture of KH2PO4 and K2HPO4. Note that KH2PO4 has one additional proton. The pKa of the acid is 6.8. Use the Henderson-Hasselbach equation (above) to calculate the ratio of [K2HPO41[KH2PO4] needed to make a solution that is pH 7.2 2. To make a solution that is 0.2 M phosphate, the concentration of KH2PO4 and K2HPO4 must add up to 0.2 M. Use the ratio you calculated above, and the...