Rusting of Iron Project
Rust is another name for iron oxide, usually red or black, which occurs when iron or an alloy that contains metal presented to oxygen and moisture for an extended period.
In the contacting with the oxygen, iron will react with the oxygen to form rust. The oxygen joins with the metal at an atomic level, building up another compound called an oxide and weakening the bonds of the metal itself. Only iron or alloys that contain iron can rust, but other metals can corrode in similar ways. Rust consists of hydrated iron(III) oxides Fe2O3•nH2O and iron(III) oxide-hydroxide (FeO(OH), Fe(OH)3).
Chemical reactions in corrosion process
There are always two different reactions happening simultaneously in a corrosion process:
1) Oxidation of Iron 2Fe —> 2Fe2+ + 4e-
2) Reduction of Oxygen O2 + 4 e- + H2O—> 4OH-
The overall reaction is:
2Fe2+ + 4OH- —-> 2 Fe(OH)2
Fe(OH)2reacts further with oxygen to form Iron oxides:
· Fe2O3 (hematite, red rust)
· Fe3O4 (magnetite, black)
Aim:- The effect of metal coupling on the rate of reaction
Beakers-15, Iron sheets of 2# size-6, Zinc sheets of 2# size-6, Measuring cylinders, Chemical Balance, Aluminum rods of 2# size-6, Brass rods of 2# size-6, weight box.
Hydrochloric acid and Sodium hydroxide
(i) Mix 9 ml. of concentrated HCl with 241 ml. of water to form 250 ml. of the solution.
(ii) Take this answer in seven different beakers.
(iii) Mark each beaker serially from 1 to 7.
(iv) Take the weights of three iron sheets, three aluminum rods, three brass rods and three Zinc sheets
(v) Hold iron sheets, aluminum rods, zinc sheets and brass rod in separate beakers
(vi) Later take iron + brass, iron + aluminium, iron + zinc, aluminium + zinc and brass + zinc and keep them in different beakers.
(vii) Enable the reactions to occur for 24 hours.
(viii) Note the maximum and minimum temperatures.
(ix) Now at the end of response take out the metals and keep them in the sun for some time so that they get dried up quickly
(x) Take the weights of each specimen and note the difference.
(xi) Similarly, repeat 1,2,3,4,5,6,7 and eight steps in a basic solution.
1. When Rust effected iron properly, each couple showed some difference in their corrosion concerning each metal kept alone.Iron + Aluminum couple has the highest rate of corrosion while iron +Zinc couple has the lowest rate of corrosion.
The rate of corrosion of each couple takes place in given order.
Iron + Aluminum > Brass + Zinc> Iron + Zinc
2.The rate of rusting of Iron is seen in acidic medium or the mass devoured amid the Corrosion is in the diminishing request from metal to aluminum. Metal has the best most astounding Corrosion rate while aluminum has the slightest consumption rate.
Metal > Iron > Zinc > Aluminum
3. The rate of rusting of Iron is seen in the essential medium is in the diminishing request from Brass to Aluminum. The request of rate of erosion is as underneath:
Metal > Zinc >Iron > Aluminum
4. Temperature and time of reaction were constant; The temperature was 21° C and time of response were 24 hours.
5. When these metals meant coupled the rate of corrosion was in the decreasing order from
Brass+ Aluminum > Brass + Zinc > Iron + Aluminum
Stainless steel forms a passivation layer of chromium(III) oxide. Similar passivation behavior also readily occurs with magnesium, titanium, zinc, zinc oxides, aluminum, polyaniline, and other electroactive conductive polymers.
Designs using this material must include measures that avoid worst-case exposures since the article continues to rust slowly even under near-ideal conditions.
Galvanization is a process that will be protected by a layer of metallic zinc by Either hot-dip galvanizing or electroplating. Zinc is generally used in light of the fact that it is cheap, holds fast well to Steel, and gives cathodic protection to the steel surface in the event of harm to the zinc layer.
Cathodic Protection is a strategy used to limit consumption on covered or immersed structures by providing an electrical charge that suppresses the electrochemical reaction. On the off chance that accurately applied, corrosion can be Stopped totally.
Coatings and Painting
Rust development may complete with coatings – like paint, finish Or varnish that disconnects the iron from nature.
Exactly when simply temporary protection required for storage or transport, a thin layer of oil, Grease, or a remarkable a mixture. Like- Cosmoline can be associated with an iron surface.
• They make genuine general medical issues.
• The investigation of the rate of consumption of various metals showed a slow abatement in their masses in acidic medium.
• The present trials are in full concurrence with the outstanding electrochemical response. A portion of the average reactions as happen with press are shown.