Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
According to this theory, the impure iron surface behaves like a small electrochemical cell presence of water containing dissolved oxygen or carbon dioxide. Such a cell is also called corrosion cell or corrosion couple. In these miniature corrosion cells, pure iron acts as anode and impure surfaces acts as cathode. Moisture dissolved oxygen or carbon dioxide in it comprises electrolytic solution.
At anode, oxidization of Fe atoms takes place. Thus, Fe atoms pass into solution as Fe2+ ions leaving behind electrons in the metal which are pushed into cathodic area. Fe Fe+2 + 2e-; = - 0.44 V (i)
At cathode, the electrons are picked up by the H+ ions which are produced either from H2O or from H2CO3 (formed by dissolution of CO2in moisture). CO2 + H2O H+ + HCO3- 2H+(aq) + 2e- 2H The H atoms, thus, formed, reduce the dissolved oxygen as 2H + ½ O2 H2O The net reduction process at the cathodic area is 2H + ½ O2 + 2e- H2O; = 1.23 V (ii)
The net reaction of the corrosion cell can be obtained by adding equations (i) and (ii) F2 + 2H+ ½O2 2 Fe2+ + H2O; = 1.67 V The ferrous ions so formed move through water and come at the surface of iron object where these are further oxidized to ferric state by atmospheric oxygen and constitute rust which is hydrated iron (III) oxide. 2Fe2+ + ½ O2 + 2H2O Fe2O3 + 4H+ Fe2+ + xH2O Fe2O3xH2O (rust)
any information of polymers
Classification of polymers - On the basis of structure On the basis of structure of polymers these can be classified as (i) Linear polymers (ii) Branched chain polym
Explain the Two solids and a solvent - Phase Diagram? The phase diagram in Figure on the next page is for a ternary system of water and two salts with an ion in common. There i
A Tris buffer at pH 6.0 (here "Tris" is a nickname use for Tris hydroxymethyl amino methane). For the given pK A table is Tris a compound you would select for a buffer at pH 6.0?
GROUP 14: TIN AND LEAD Tin and lead give some resemblance to the lighter elements in group 14, especially Ge. Although they are uniquely more metallic in their physical and chem
What is difference among silica used in TLC and HPLC column? Ans) TLC is known as thin layer chromatography. The simple methods works on the principle of adsorption, where as HP
Burgers vector in screw dislocation The Burgers vector, often signified by b, is a vector that shows the magnitude and direction of the lattice distortion of dislocation in a
#question.what is chemical structures and names of first 20 mono carboxylic acid? .
The magnetic quantum number for valency electrons of sodium is: (1) 3 (2) 2 (3) 1 (4) 0 Ans: 0
what is castner kellner process
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd