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

Define and classify alkanes, Question 1 Write a short note on the followin...

Question 1 Write a short note on the following Photoelectric effect Transition Elements Hydrogen bonding Standard entropy Question 2 What are aromatic acids

Cyclic or closed chain compounds, Cyclic or closed-chain compounds Cyc...

Cyclic or closed-chain compounds Cyclic compounds consist of at least one ring or closed chain of atoms. The compounds along with just only one ring of atoms in the molecule a

Photochemistry, what are the practical applications of photochemistry

what are the practical applications of photochemistry

Quantum numbers of an atom can be defined on the basis, Quantum numbers of ...

Quantum numbers of an atom can be defined on the basis of: (1) Hund's rule (2) Aufbau's principle (3) Pauli's exclusion principle (4) Heisenberg's uncertainty principl

Chemical properties of aromatic nitro compounds, Chemical Properties of Aro...

Chemical Properties of Aromatic Nitro Compounds Resonance in nitrobenzene pass on a partial double bond character to the bond among carbon of benzene nucleus and nitrogen of th

Henderson-hasselbalch equation, (a) Explain in terms of ionic equilibria wh...

(a) Explain in terms of ionic equilibria why the aqueous solution of a salt derived from a weak acid and a strong base (e.g. sodium phenolate) has a pH greater than 7. (b) B

Expressing quantities in scientific notation, The surface area of the Pacif...

The surface area of the Pacific Ocean is 166000000000000m 2 . Write this quantity in scientific notation. To write the amount in scientific notation move the decimal point to after

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

Physical properties of monohydric alcohols, Physical properties of monohydr...

Physical properties of monohydric alcohols (a) Character - Monohydric Alcohols are neutral component. These comprise no effect on litmus paper. This is analytical investigation

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