2016年2月14日 · Meanwhile for phosphate buffer, the pKa value of #H_2PO_4^-# is equal to 7.2 so that the buffer system is suitable for a pH range of #7.2+-1# or from 6.2 to 8.2. Since the target pH of the buffer to be prepared is 5.0, the best buffer system to use will be the acetate buffer since 5.0 fall in the maximum buffering range for this buffer system.

For example, blood contains a carbonate/bicarbonate buffer that keeps the pH close to 7.4. Biochemical Assays. Enzyme activity depends on pH, so the pH during an enzyme assay must stay constant. In shampoos. Many shampoos use a citric acid/sodium citrate shampoo to maintain a slightly acidic "pH balance".

2014年12月26日 · When too much protons are added to the blood, the buffer system gets a little help from the lungs and the kidneys: The lungs remove excess #CO_2# from the blood #-># this increases the pH; The kidneys remove excess #HCO_3^(-)# from the body #-># this lowers the pH. Here's a nice video detailing the carbonic acid - bicarabonate ion buffer system:

2016年12月26日 · Carbonates will (partly) neutralize the acid, so pH goes up. This is due to the reaction: 2H_3O^+(aq) +CO_3^(2-)(aq) ->3H_2O(l)+CO_2(g) or: 2H^+(aq) +CO_3^(2-)(aq ...

2014年4月6日 · You find an acid with a "p"K_"a" close to 12. Then you make a solution of the acid and its conjugate base in the correct proportions. > The only common acids with "p"K_a" ≈ 12 are "H"_3"PO"_4 with "p"K_text(a3) = 12.35 and ascorbic acid, "H"_2"C"_6"H"_6"O"_6 with "p"K_text(a2) = 11.79.

2016年1月1日 · Here's what's going on here. The main buffer system used to control the pH of the blood is the bicarbonate buffering system. This buffer system revolves around the amount of carbon dioxide dissolved in the blood and on the amount of bicarbonate anions, "HCO"_3^(-), present in the blood. More specifically, it consists of carbonic acid, "H"_2"CO"_3, weak acid, in …

A buffer solution will maintain a constant pH with the addition of small amounts of acid and alkali. There is a limit to the amount of acid or alkali that the buffer can handle. The buffer capacity is given by the expression: #(dn)/(d(pH))# #dn# is a tiny amount of added base which results in tiny change in pH shown as #d(pH)#

2014年7月5日 · A buffer resists changes to pH when small amounts of strong acid or base are added to it. Buffers have many applications. Some of these are Maintenance of life Most biochemical processes work within a relatively small pH range. The body uses buffers solution to maintain a constant pH. For example, blood contains a carbonate/bicarbonate buffer that …

2014年4月14日 · All buffer solutions consist of a mixture of an acid with its conjugate base. Calculate pH using the Henderson-Hasselbalch equation, which requires the Ka of the acid and the relative concentrations of acid and base. This works for polyprotic acids, too. Example: For a mixture of sodium carbonate and sodium bicarbonate, the bicarbonate is the acid and the …

2016年12月27日 · An acid buffer is a solution that contains roughly the same concentrations of a weak acid and its conjugate base. Thus, an acetate buffer contains roughly equal concentrations of acetic acid and acetate ion. They are in a chemical equilibrium with each other. The equation is: