Buffer capacity refers to the amount of acid or base a buffer can absorb without a significant pH change. It is governed by the concentrations of the conjugate acid and base components of the buffer. A 0.5 M buffer can "absorb" five times as much acid or base as a 0.1 M buffer for a given pH change. In this problem you begin with a buffer of known pH and concentration and calculate the new pH after a particular quantity of acid or base is added. 4. You are given 60 mL of 0.50 M phosphate buffer, pH = 6.83, to test. The starting composition of the buffer, both in terms of the concentration and the molar quantity of the two major phosphate species, is: Concentration of HPO,²: 0.304 M Molar quantity of HPO,: 18.2 mmol Concentration of H,PO*: 0.196 M Molar quantity of H,PO = 11.8 mmol You add 1.7 mL of 1.00 M HCl to the buffer. Calculate the molar quantity of H,O* added as HCl, and the final molar quantity of HPO, and H,PO,¯ at equilibrium. a. b. What is the new HPO/H,PO,¯ ratio, and the…

A series of carbonic acid or carbonate buffers regulate pH in blood within the human body. The kidneys and the lungs work together to help maintain a blood pH of 7.4 by affecting the components of the buffers in the blood. What conjugate acid/base pair is the main component in the buffer? Write out the chemical reaction that the conjugate pair undergoes in water. What is the ratio of the acid to the base? What is the ideal pH range for this buffer? Is the pH of blood within the ideal range of the buffer? If it is not, what is the physiological reason that the body would have for still using a carbonate buffer as opposed to another conjugate pair?

A chemistry graduate student is given 450. mL of a 1.70M hydrocyanic acid (HCN) solution. Hydrocyanic acid is a weak acid with K,= 4.9 × 10 ". What mass of KCN should the student dissolve in the HCN solution to turn it into a buffer with pH = 8.97? You may assume that the volume of the solution doesn't change when the KCN is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.