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)
Glucose and fructose are epimers so they are differ in their second carbon position and remaining is same so when they react with phenylhydrazeen they give same osazone
transition elements form coloured compound. Why?
You are given a sample block of an unknown metal. The block displaces 3.24 mL of water and has a mass of 62.5429 g. What is the density of the unknown metal? What is the metal?
If you have 250 mL of 2 M sodium sulfate diluted to make 0.500 M of sodium sulfate, how would you figure out the volume?
why methane does not absorb IR radiation?
Q. Example to show scientific notation? Solve the following problem. 2.45 *10 14 kg + 4.00 * 10 12 kg First articulate both quantities to the same power of ten. Either
Q. Describe about states of matter? Under usual conditions matter exists in three different physical forms called the states of matter -solid or liquid or gas. Solid matter
Q. A sample of water analysis was found to contain temporary magnesium hardness 25 mg/L. Permanent magnesium chloride hardness 15 mg/L and permanent calcium sulphate hardness 20
I have the following reactions (1)NaOH+CO2+M=NaHCO3+M, K1 (2)NaHCO3+H=Na+H2CO3, K2 (3)2NaHCO3+M=(NaHCO3)2+M, K3 ki''s are the rate constants. Suppose NaHCO3 is a dominating constit
In lab, buffers solution based onto a 0.1 M solution of sodium phosphate at pH7.0. Within this system, there are three of pK A s like: 12.7, 7.21 and 2.12. Determine the conce
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