Henderson Hasselbalch Equation For Base

Assumptions for the henderson hasselbalch equation.

Henderson hasselbalch equation for base. It is defined as. Lawrence joseph henderson 1878 1942 was a talented biochemist among many other titles who spent most of his career at harvard. Lawrence joseph henderson and karl albert hasselbalch. The henderson hasselbalch equation provides a general solution to the quantitative treatment of acid base equilibrium in a biological system.

To the henderson hasselbalch equation return to the acid base menu problem 31. 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. Buffers are the mixture of weak acids and their salts of strong bases or the mixture of weak bases and their salts of strong acids simply buffers are an important concept of acid. How much sodium formate hcoona 68 0069 g mol do you need to add to 400.

Calculate the ph of a buffer solution made from 0 20 m hc 2 h 3 o 2 and 0 50 m c 2 h 3 o 2 that has an acid dissociation constant for hc 2 h 3 o 2 of 1 8 x 10 5. The buffer ph can be estimated using the henderson hasselbalch equation which is ph pka log a ha. Since a buffer is intended to give only a small change in ph with added h or oh the best buffer for a given ph is the one that gives the smallest change as may be seen from the henderson hasselbalch equation when the ph of the solution equals the pk of the buffer conjugate base acid and the buffer can therefore respond equally to both added acid and added base. This article explains how to derive the henderson hasselbalch equation.

The henderson hasselbalch equation is a tool that allows us to calculate the ph of an acid solution using the pka of the acid and the relative concentrations of the acid and its conjugate base. Example problem applying the henderson hasselbalch equation. This works when water is the solvent and is present in a very large proportion to the h and acid conjugate base. 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.

The henderson hasselbalch equation provides a relationship between the ph of acids in aqueous solutions and their pk a acid dissociation constant. The reason the henderson hasselbalch equation is an approximation is because it takes water chemistry out of the equation. Ml of 1 00 m formic acid for a ph 3 500 buffer. The equilibrium between the weak acid and its conjugate base allows the solution to resist changes to ph when small amounts of strong acid or base are added.