Henderson Hasselbalch Equation Calculator

The Henderson Hasselbalch equation calculator is a basic scientific device for determining whether a buffer solution is acidic or alkaline. The calculator can be used to assume the pH of a solvent, as well as the acid level and conjugate base present. The Henderson Hasselbalch calculator application speeds up the calculation and provides the hydrogen ions in seconds. We’ll go over the concept and show you how to utilize the Henderson Hasselbalch equation to calculate the acidity and alkalinity of a biological process in the article below.

What is Henderson Hasselbalch Equation                              

According to biochemistry experts, the Henderson Hasselbalch equation is used to compute the concentration of hydrogen ions (acidity or alkalinity) in an aqueous solution containing a weak acid and its conjugate base. Strong acid and a weak conjugate base, or a strong base and a weak conjugate acid, are vividly present in the sample. The acid is a proton giver, whereas the base is a proton receiver. The Henderson Hasselbalch equation to estimate the hydrogen ion concentration in the solution is

pH = pKa + log ([A]/[HA])


A represent the molar concentration of conjugate base
HA represents the molar concentration of the acid solution
pK represents the acid dissociation constant.

The Henderson Hasselbalch equation logically relates a solution’s measured pH with the acid’s pKa (that equals -log Ka). The formula can also be used to calculate the pH of a buffer solution or the equilibrium pH of an acid-base reaction. The pKa formula for weak acid or buffer can be used to get the equation.

When the Henderson Hasselbalch equation is employed in an acid-base titration, it is undesirable since it yields the same result for any used concentration of weak acid and strong base, and after initiating the titration and applying the base, pH readings are lesser than the weak acid’s original pH. The inclusion of a strong base cannot logically describe the decrease in pH because all chemistry textbooks state that the pH values rise when a strong base is added to a weak acid solution.

The Henderson Hasselbalch equation drawback, we believe, is to blame for this strange and incorrect scenario. The drawback is that during titration, the Henderson Hasselbalch equation presupposes that the summation of the weak acid and conjugate base concentrations of a weak acid is constant. Assuming it does not analyze acid fragmentation and conjugate base hydrolysis, the total of the weak acid and conjugate base concentrations will remain constant.

Concept of Henderson Hasselbalch Equation

  • An acid that is the molar concentration of the acid can give a proton that is the hydrogen ion concentration whereas a base can receive one, as per the Bronsted-Lowry theory of acids and bases.
  • The molar concentration of a conjugate base is set when an acid gives a proton, and the protonated base appears as conjugate acid.
  • The following equations show how acid breaks down:

HA ↔  H+ + A

This correlation can be deduced from the viewpoint of the balanced equation.

What is the importance of the Henderson Hasselbalch Equation?

Determining ionized and conjugated chemical densities.

The capacity to measure the amounts of ionized and unionized compounds is one of the best-advanced capabilities of the Henderson Hasselbalch equation. In most cases, spectroscopic techniques are used to determine the concentration of ionized and unionized species, hence this equation is useful when spectroscopic experiments are not possible. In areas like hydrocarbons, logical chemistry, and medicine, knowing the concentration of ionized and unionized chemicals is crucial.

Determining the acidity of a buffer solution with the help of acid dissociation constant

This formula can be employed to calculate the acidity and alkalinity of various buffers in chemical equations and biochemical pathways such as enzymes and proteins.

Determining how acidity or alkalinity affects solubility

The Henderson Hasselbalch equation is useful in estimating the pH dependence of solubility. The solubility of a solution can be calculated depending on its pH, and there is a clear correlation between both pH and the solubility of various components in a solution.

Determining a protein’s electrochemical potential

The isoelectric point of many proteins can also be determined using this equation, that is the level of acid/base at which proteins neither donate nor take protons.

Using pH to determine the acid dissociation constant of a compound

The acid dissociation constant of a chemical compound must be determined since it is a key property of the chemistry of the molecule’s composition. When the proportion of ionized and unionized compounds and the pH of the solution are identified, the Henderson Hasselbalch equation can be applied to calculate the acid dissociation constant.

Restrictions of Henderson Hasselbalch Equation

  • The primary essential hypothesis in this equation is that all through the solution, the ph level, and its conjugate base will remain constant.
  • The importance of water hydrolysis and its impact on the pH of the entire solution is often overlooked.
  • Likewise, the hydrolysis of the base and acid dissociation is not taken into account.
  • When engaging with strong acids or bases, the assertion made in the equation may fail.

How to Use or Operate the Henderson Hasselbalch Calculator

The following is how to operate the Henderson Hasselbalch calculator:

Step 1: In the input field, type the molar concentration of the conjugate base, acid, and dissociation constant.
Step 2: To get the answer, press the icon Solve pH.
Step 3: Lastly, in the result tab, the pH of the solution of the buffer solution will be presented.

Advantages of Henderson Hasselbalch Equation

The following are the primary goals of the Henderson Hasselbalch equation:

  1. It’s used in explaining the buffer capability.
  2. It is used to assess the proton transfer condition of various biomolecule functional units in a pH seven solution
  3. It demonstrates how to define the preparation of either an acidic or basic buffer solution.
  4. It can be used to estimate if a buffer solution of NaCl will have a high concentration of acid, basic, or neutral depending on the readings of the acid dissociation constant and base dissociation constant for conjugate acid-base pairs.
  5. It is used to estimate the acidity and alkalinity, hydroxide ion concentration of a solution, hydronium ion concentration, Hydroxide, Hydronium ion water, hydroxide water in a solution with a strong acid (base) by using the original proportion of the acid (base).
  6. It’s used in explaining what a buffer solution is.
  7. It’s used to demonstrate how the proximate vitalities of conjugate acids or bases can be measured using the base dissociation constant and acid dissociation constant readings for bases and acids, accordingly.
  8. It explains how a buffer solution (acidity or alkalinity) can withstand substantial pH changes when modest volumes of acid or base are administered to the buffer solution.


Is it possible to apply pKb to the Henderson Hasselbalch equation?

The Henderson Hasselbalch equation can be rewritten in the following way for bases:
pOH = pKb + log ([B+]/[BOH])
pKb is the dissociation constant of the base,
[B+] is the concentration of the conjugate acid of the base, and
[BOH] is the concentration of the base.

Is it possible to accomplish the Henderson Hasselbalch using KB?

When working with a weak acid and knowing the Ka, the Henderson-Hasselbalch equation can be applied. If you’re provided Kb and you’re working with a weak base, you’ll need to utilize the correct Kb equation

How can you use the Henderson Hasselbalch equation to make a buffer solution?

According to the Henderson Hasselbalch equation, the ionic strength of the buffer solution is equivalent to the weak acid’s acid dissociation constant and as well as the logarithm of the ratio of the conjugate base concentration divided by the weak acid’s concentration. Acetic acid is the weak acid in the salt solution.

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