How would you increase the buffering capacity of a buffer made by adding NaHCO2 to an aqueous solution of HCO2H?
(a) increase the concentration of HCO2H.
(b) increase the concentration of NaHCO2.
(c) increase the concentrations of both HCO2H and NaHCO2.
(d) increase the ratio of the concentration of HCO2H to NaHCO2.
(e) increase the ratio of the concentration of NaHCO2 to HCO2H.
Chemistry · Sun Jul 10 2022
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To increase the buffering capacity of a buffer made by adding NaHCO2 to an aqueous solution of HCO2H, you can take the following steps:
1. Increase the concentration of HCO2H: By increasing the concentration of the weak acid, HCO2H, in the buffer solution, you can increase the amount of acid available to react with any added base and maintain the pH of the solution. This will increase the buffering capacity of the solution.
Extra: A buffer solution is a solution that can resist changes in pH when small amounts of acid or base are added to it. It consists of a weak acid and its conjugate base (or a weak base and its conjugate acid). In this case, HCO2H is the weak acid and NaHCO2 is its conjugate base.
2. Increase the concentration of NaHCO2: By increasing the concentration of the conjugate base, NaHCO2, in the buffer solution, you can increase the amount of base available to react with any added acid and maintain the pH of the solution. This will also increase the buffering capacity of the solution.
Buffering capacity refers to the ability of a buffer solution to resist changes in pH. It depends on the concentrations of the weak acid and its conjugate base in the solution. A higher concentration of either component will result in a higher buffering capacity.
3. Increase the concentrations of both HCO2H and NaHCO2: Increasing the concentrations of both the weak acid and its conjugate base will result in a higher buffering capacity. This is because there will be more acid and base available to neutralize small amounts of added acid or base and maintain the pH of the solution.
4. Increase the ratio of the concentration of HCO2H to NaHCO2: Adjusting the ratio of the weak acid to its conjugate base can also increase the buffering capacity. If the concentration of HCO2H is much higher than NaHCO2, the solution will be more acidic and will be better able to resist changes in pH caused by the addition of a base. This is because the excess acid can react with the base to maintain the pH.
5. Increase the ratio of the concentration of NaHCO2 to HCO2H: Conversely, if the concentration of NaHCO2 is much higher than HCO2H, the solution will be more basic and will be better able to resist changes in pH caused by the addition of an acid. This is because the excess base can react with the acid to maintain the pH.
Overall, the buffering capacity of a solution can be increased by adjusting the concentrations and ratios of the weak acid and its conjugate base in the buffer solution. The specific method chosen will depend on the desired pH range and the specific needs of the experiment or reaction.