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

Tf-block elements.., lanthanoids with +4 o.s act as strong oxidising agents...

lanthanoids with +4 o.s act as strong oxidising agents even though it is in stable configuration f zero

Functional groups - iupac system of naming organic compounds, Functional gr...

Functional groups - IUPAC System of Naming Organic Compounds If a compound involves much more than one functional group, as compared to one of the functional group is considere

Determine electrons in carbon atom, The number of unpaired electrons in ca...

The number of unpaired electrons in carbon atom in excited state is: (1) One  (2) Two          (3) Three      (4) Four Ans: Four

Necessary precautions for quick vinegar process, Necessary Precautions for ...

Necessary Precautions for Quick Vinegar Process In this process, the following precautions are necessary: a. The concentration of the ethyl alcohol could not be much more th

What is law of definite proportions, Q. What is law of definite proportions...

Q. What is law of definite proportions? A given compound is forever composed of the same elements in the same proportion by mass. This fact is recognized as the law of definit

Suffix - iupac system of naming organic compounds, Suffix - IUPAC System of...

Suffix - IUPAC System of Naming Organic Compounds The word root is associated to the suffix that may be primary or secondary or both of them. (a) Primary suffix: A

Indicate the nature of bonding, Indicate the nature of bonding in CCl 4   a...

Indicate the nature of bonding in CCl 4   and  CaH 2 : (1) Covalent in Ccl 4    and electrovalent in  Cah 2 (2) Electrovalent in both CCl  and CaH 2 (3) Covalent in bot

The statements, The statements: (1)  In filling a group of orbitals of equ...

The statements: (1)  In filling a group of orbitals of equal energy, it is energetically preferable to assign electrons to empty orbitals rather than pair them into a particular o

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