0

Guest

Courses New

what is hydrolysis AND ITS SIGNIFICANCE WITH ACID AND BASE STRENGTH

what is hydrolysis AND ITS SIGNIFICANCE WITH ACID AND BASE STRENGTH

Grade:

2 Answers

Saurabh Kumar
24 Points
9 years ago
Hydrolysis is a reaction involving the breaking of a bond in a molecule using water. The reaction mainly occurs between an ion and water molecules and often changes the pH of a solution. In chemistry, there are three main types of hydrolysis: salt hydrolysis, acid hydrolysis, and base hydrolysis.
Raheema Javed
156 Points
9 years ago
Hydrolysis means "cleavage by means of water". There are many different types of hydrolysis reaction, but in this problem, hydrolysis refers to a reaction between water and the anion of the weak acid. For example, the acetate ion hydrolyzes according to:C2H3O2-(aq) + H2O(l) = HC2H3O2(aq) + OH-(aq)You would expect a solution of sodium acetate to be somewhat basic because of the hydroxide produced by this reaction. But how basic will the solution be?

The pH of the solution depends on the how strong a base the hydrolyzing anion is. The stronger the acid that forms from the hydrolysis, the weaker the hydrolyzing anion is as a base. It does make sense: The stronger an acid is, the more easily it gives up hydrogen ions, so the anion formed in the dissociation must not hang on to hydrogen ions very tightly.

This reciprocal relationship between strength of the acid and the conjugate anion base can be expressed quantitatively using equilibrium constants. The equilibrium constant for the basic hydrolysis Kb can be calculated from the the equilibrium constant for the acid dissociation Ka as Kb = Kw/Ka, where Kw is the equilibrium constant for dissociation of water into H+ and OH-(aq) (equal to 1.0x10-14.
Hydrolysis equilibria must be accounted for if you want to accurately estimate the pH of any solution that contains appreciable quantities of the anion of a weak acid. There are really two places on the titration curve where hydrolysis equilibria are important: near the equivalence point, and in the buffer region.

pH in the buffer region is usually computed by solving a system of equilibrium constant, mass balance, and charge balance equations (or more simply and approximately using the Henderson-Hasselbach equation). The buffer region is a story for another time, but here is how you can use hydrolysis equilibria to compute the pH at the equivalence point of the titration.

Think You Can Provide A Better Answer ?

Other Related Questions on Physical Chemistry

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More