Henderson Hasselbalch Equation Ph

The henderson hasselbalch equation can be used to calculate the ph of a solution containing the acid and one of its salts that is of a buffer solution.

Henderson hasselbalch equation ph. How to calculate ph and pka of a buffer using henderson hasselbalch equation. Ph pka and henderson hasselbalch equation the pka is the ph value at which a chemical species will accept or donate a proton. Chemically a buffer is a solution of equimolar concentration of a weak acid such as acetic acid ch 3 cooh and its conjugate base such as. Henderson hasselbalch equation is a numerical expression which relates the ph pka and buffer action of a buffer.

The chances increase the further above pka you are. The henderson hasselbalch equation describes the relationship of ph as a measure of acidity with the acid dissociation constant pka in biological and chemical systems. The lower the pka the stronger the acid and the greater the ability to donate a proton in aqueous solution. The basic equation is as follows.

We have already seen the derivation of the henderson hasselbalch equation on this page we discuss some of the applications of the henderson hasselbalch equation and solve some sample problems which one may encounter in research. Example problem applying the henderson hasselbalch equation. The henderson hasselbalch equation is widely used by many scientists especially chemists biologists and pharmacists. A buffer is a solution which can resist the change in ph.

The henderson hasselbalch equation describes the derivation of ph as a measure of acidity using pka the negative log of the acid dissociation constant in biological and chemical systems. The equation is especially useful for estimating the ph of a buffer solution and finding the equilibrium ph in acid base reactions. With bases if the value of an equilibrium constant is known in the form of a base association constant k b the dissociation constant of the conjugate acid may be calculated from pk a pk. The ph of a buffer solution can be estimated with the help of this equation when the concentration of the acid and its conjugate base or the base and the corresponding conjugate acid are known.

The henderson hasselbalch approximation allows us one method to approximate the ph of a buffer solution. Ph approx pk a log 10 dfrac a ha we have straightforward calculations for strong acids and bases but the computations behind buffers are rather complex and time consuming. Ph pka log a ha pka is the ph which 1 2 of the acid molecules have given up a h any ph higher than an acid s pka a molecule of that acid is more likely to be deprotonated than protonated.