Henderson Hasselbalch Equation

You can see the relationship between the pH or pOH of a solution and the pKa or pKb of the solution, as well as the ratio of the concentrations of different dissociated chemical species, using the Henderson Hasselbalch equation. Before the equation can be used, the acid dissociation constant must be known.

In 1908, Lawrence Joseph Henderson devised an equation for calculating the pH of a buffer solution. Karl Albert Hasselbalch rewrote the formula in 1917 using logarithmic terms.

Difference between volume and the Henderson-Hasselbalch equation?

As a result, the Henderson-Hasselbalch equation is unaffected by container volume. The Henderson-Hasselbalch equation is treated as a simple equation in this case, with none of the limitations taken into account.

The limitations of the Henderson-Hasselbalch equation

There are several flaws in the Henderson-Hasselbalch Equation.

The Henderson-Hasselbalch equation does not provide accurate pH values for extremely dilute buffer solutions because it does not account for the self-dissociation that occurs in water.

The Significance of the Henderson-Hasselbalch equation

Estimating the pH of a buffer solution and determining the equilibrium pH of an acid-base reaction are two applications of the Henderson-Hasselbalch equation.

Source of the Henderson-Hasselbalch equation

The Henderson-Hasselbach equation is a formula that describes the relationship between the acid dissociation constant and the pH of an aqueous solution of an acid. The acid dissociation constant must be defined first in order to derive the Henderson-Hasselbach equation.

Although the Henderson-Hasselbalch equation can be useful in a variety of situations, it is not always accurate.

This equation will produce poor or inaccurate results if strong acids or bases are present. While pKa values in the range of 5 to 9 are usually accurate, when we go outside of this range, the pH value is more likely to be incorrect.

Use of the Henderson-Hasselbalch equation 

In a variety of situations, the Henderson Hasselbalch Equation is used.

Knowing the formula for pH value, which is expressed as acidity, can help both chemical and biological systems. The following formula is used to calculate the pH of a buffer solution made by mixing salt with a weak acid or base: pKa is a pH constant that is used to calculate the pH. Calculate the buffer solution’s pH.

Possibility to solve the Henderson-Hasselbalch equation with moles

We can calculate the moles of acetic acid using M = mol/L, which gives us mol = ML = (2M) * (0.5L) = 1mol acetic acid. Using the Hendersen Hasselbach equation, it is possible to see that the pH equals the pKa when the concentration of conjugate base (acetic acid) equals the concentration of acid.

Buffers derived from the Henderson-Hasselbalch equation for buffers

Using a buffer as a solution: When a small amount of acid or base is added to a buffer solution, the pH of the solution does not change. A buffer solution is defined as a solution that can withstand a pH change when a small amount of acid or base is added to it. Henderson-Hasselbaltch.

The method for obtaining the Henderson-Hasselbalch equation for weak bases?

This equation makes calculating the pH of a solution containing a weak acid and its conjugate base much easier (or salt). In a similar way, the equation for a buffer solution, which is a mixture of a weak base and its salt, is obtained.

Which is more common: acid ionisation or acid unionisation?

Weak acids and bases become 50% ionised and 50% unionised when the surrounding pH equals the drug’s pKa. At pH values 2 pH units above or below the drug’s pKa, nearly all of the drug is ionised or unionised.

Conclusion:- 

If we know the final concentrations of the acid and base, as well as the pKa of the buffer solution, we can use the Henderson–Hasselbalch equation to calculate the pH of a buffer solution. In this lab, we learned how to use the equation to calculate the final concentrations of the weak acid and its conjugate base, which we then entered into the equation to determine the calculated pH. Buffers, as well as the process of making our own, were introduced to us in this lab. We also learned about titration curves and had to make two of them for a lab section where we were working. Titration curves can be very descriptive if done correctly because they visually indicate the pKa value as well as the buffer zone of a solution. On the whole, this lab had a low rate of errors. Any potential errors could have resulted from us inadvertently entering the wrong value when running the simulation. However, it does not appear that this was the case in this lab. Other errors could result from the calculations in which I determined the pH of solutions myself. However, this lab did not perform enough calculations to rule out the possibility of a large number of errors.