Deriving Henderson-Hasselbalch Equation Step by Step. The Relationship between pH, pKa, Titration Curve and Buffer Action of a Weak Acid. The Significance. Derivation of the Henderson –Hasselbalch Equation for weak base. B + HOH. BH . +. + OH. – or. B. –. + HOH. BH + OH. –. Either one works, but you have to be. Henderson–Hasselbalch equation describes the derivation of pH as a measure of acidity using the acid dissociation constant (pKa.

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Deriving the Henderson-Hasselbach Equation

However, these are related by the equation: Later, Karl Albert Hasselbalch re-expressed that formula in logarithmic terms, resulting in the Henderson—Hasselbalch equation.

Views Read Edit View history. When we prepare a solution by mixing 0. The titration curve of a weak acid helps to determine the buffering pH which is exhibited around the pKa of that acid. The Henderson-Hasselbach equation derived from the equilibrium expression of hydrofluoric acid. After derivahion manipulations we can return to our yellow highlighted equation.

Sorry, your blog cannot share posts by email. In this simulation, we will use KA for the acid dissociation constant.


Leave a Reply Cancel reply You must be logged in to post a comment. Multiply both sides by [HF] and then divide both sides by [F-] to get by itself.

For the standard base equation: Henderson-Hasselbalch equation is a simple expression which relates the pHpKa and the buffer action of a weak acid and its conjugate base. WikiProject Chemistry may be able to help recruit an expert.

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The dissociation derivatuon Ka of the above reaction will be: Proton Hopping in Water. For example, in the case of acetate buffer, the pKa is 4. Bracketed quantities such as [base] and [acid] denote the molar concentration of the quantity enclosed.

Physical and Biological Properties of Water.

Here you will see me using the exponent rule Now a logarithm rule: In my next post, I will discuss the similarities eequation differences between using an ICE table versus using the Henderson-Hasselbach equation. This article has multiple issues. Similar problem is present in calculation of pH of diluted buffers. Sometimes these other units are more convenient to use. However, the same equation will work perfectly regardless of the pKa value if you are asked to calculate ratio of acid to conjugate henderosn in the solution with known pH.

Further calculations depend on haswelbalch way you want to prepare the buffer. Henderson—Hasselbalch equation describes the derivation of pH as a measure of acidity using the acid dissociation constant pKa, in biological and chemical systems. February Learn how and when to remove this template message.


Henderson-Hasselbalch equation is used mostly to calculate pH of solution which is obtained by mixing known amount of acid and conjugate base or neutralizing part of acid with strong base.

We have already stated that for a buffer the best buffering pH is at its pKa.

Deriving the Henderson-Hasselbach Equation » Science Matters

In analogy to the above equations, the following equation is valid: Retrieved 27 March In this post, I will derive the Henderson-Hasselbach equation from the equilibrium expression. Retrieved from ” https: Julian—Gregorian uncertainty Use dmy dates from September Titration Curve of Weak Acid.

Taken together, the following equation can be used to relate the pH of blood to the concentration of bicarbonate and the partial pressure of carbon dioxide: