Ph scale, Chemistry

Assignment Help:

Being simultaneously basic and acidic, water undergoes autoprotolysis, also called self-ionization:

1192_Untitled.png

The equilibrium constant is

1847_Untitled.png

 

H3O+ in these equations is general simply written H+. In pure water and in solutions that do not give any additional source of H+ or OH- both ions have molar concentrations exact to 10-7. Addition of an acid decreases [OH-] and hence increases [H3O+]; addition of a base has the reverse effect.

 

The pH scale is defined by

 

450_Untitled.png

Neutral water has a pH of 7, acidic solutions have lower values of ph (typically 0-7), and basic solutions or alkaline higher values (7-14). In alkaline or basic solutions [OH-] is thus greater than [H+].

 

Strong and weak behavior

The equilibrium constant of the protolysis reaction

 

451_Untitled.png

is known as the acid dissociation constant (Ka) of HA or the acidity constant:

 

219_Untitled.png

It is often expressed as a pKa value, described as

 

80_Untitled.png


Related Discussions:- Ph scale

How reliable are measurements, Q. How reliable are measurements? When s...

Q. How reliable are measurements? When scientists glance at measurements they want to know how accurate as well as how precise the measurements are. Accuracy demotes to how c

Dextrorotary compounds and levi rotary compounds, What are dextrorotary com...

What are dextrorotary compounds and Levi rotary compounds? Ans) Compounds that rotate the plane polarized light to the right are known as Dextro rotatory compounds and that rota

Valence Bond Theory, What are the limitations of valence bond theory?

What are the limitations of valence bond theory?

Chromatography, The process of chromatography involves passing a mixture di...

The process of chromatography involves passing a mixture dissolved in the "mobile phase" through a stationary phase, which separates the analyte which is to be measured from the ot

Metal carbonyls, what is the magnetic behaviour of metal carbonyls

what is the magnetic behaviour of metal carbonyls

Free radical aromatic substitution - hydrocarbon, Free radical aromatic sub...

Free radical aromatic substitution - Hydrocarbon The aromatic substitution reactions that follow free radical mechanisms are extremely few and have limited synthetic value. Alt

In how many chlorines does slicon bound, In how many chlorines does Slicon ...

In how many chlorines does Slicon bound The sito four chlorines, and is thus tetrahedral. The Cl-Si-Cl bond angle is 109.5°.

Extraction of metals, metals iron, aluminium, copper, gold, etc. have great...

metals iron, aluminium, copper, gold, etc. have great industrial significants. which are their important ores? important alloys of iron, aluminium and copper and their uses.

Fractional crystallisation- purification of organic compound, Fractional cr...

Fractional crystallisation- Purification of organic compound The method of separation of diverse components of a mixture by repeated crystallisations is termed as fractional cr

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd