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 to determine wavelength of electromagnetic waves, Q. How to determine w...

Q. How to determine wavelength of electromagnetic waves? The frequency as well as velocity of a wave determines its wavelength the distance between equivalent points on a con

Physical and chemical properties of phenols? , Phenols : Physical propertie...

Phenols : Physical properties: 1.Low molecular weight phenols are normally liquids or low melting solids 2.Due to H- bonding ,most low molecular weight phenols are water soluble 3.

What is peroxodisulphuric acid, Q. What is Peroxodisulphuric Acid? It i...

Q. What is Peroxodisulphuric Acid? It is also known as perdisulphuric acid or simply persulphuric acid. The acid can be obtained  by the action of chlorosulphonic acid on H 2 0

the rate of entropy change within the turbine , An adiabatic air compresso...

An adiabatic air compressor is to be powered by a direct-coupled adiabatic steam turbine that is also driving a generator. Steam enters the turbine at 12.5 MPa and 500oC at a rate

Measure the average molecular weight, Suppose you are required to make an a...

Suppose you are required to make an analysis of 317 lb of combustion gas and find it has the following composition: CO 2  60% CO    10% N 2      30% a)  What it the av

Titrations, hi I''m doing an assignment and one question has came up saying...

hi I''m doing an assignment and one question has came up saying describe 3 different titrations that are not volumetric, I''ve been searching since yesterday but still have no clue

Organic, which is more acidic 3 floro pentonoic acid or 3 nitro pentonoic a...

which is more acidic 3 floro pentonoic acid or 3 nitro pentonoic acid

Explain the molecular basis for the rigor state, 1.  The pH of a 0.02 M sol...

1.  The pH of a 0.02 M solution of an acid was measured as 4.6.              a) What is the [H + ] of the solution?             b) What is the acid dissociation constant K an

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