Corrosion and its Prevention
Corrosion and its Prevention
Corrosion:
It is the slow process of eating away of metals by the reaction of atmospheric air and moisture, e.g. rusting of iron, tarnishing of silver, formation of green coating over copper etc.
When a copper vessel is exposed to moist air for long, it acquires a dull green coating. The green material is a mixture of copper hydroxide and copper carbonate
. The reaction involved is
• Iron reacts with oxygen and moisture present in the atmosphere to form a brown, flaky substance called rust. Rusting of iron in an undesirable reaction because the layer of rust formed falls off, exposing the metal to further rusting.
Prevention of Corrosion:
Rusting of iron is prevented by galvanizing, by making alloys, painting greasing or oiling and tin- planting and chromium plating which are explained below:·
1. Galvanisation: The process of coating iron and steel objects with a thin layer of zinc is called galvanization. It is done by dipping the object in molten zinc.The galvanized article is protected against rusting even if the zinc coating is broken.·
The metal which is not corroded by air, water and acids is __________________ | |||
| Right Option : D | |||
| View Explanation | |||
22-carat gold is a mixture of _________________ | |||
| Right Option : A | |||
| View Explanation | |||
Silver articles become _________________ after some time when exposed to air. | |||
| Right Option : A | |||
| View Explanation | |||
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My experience with Abhyas is very good. I have learnt many things here like vedic maths and reasoning also. Teachers here first take our doubts and then there are assignments to verify our weak points.
Shivam Rana
7thA marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
Archit Segal
7thI have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
Yatharthi Sharma
10thAbhyas is a complete education Institute. Here extreme care is taken by teacher with the help of regular exam. Extra classes also conducted by the institute, if the student is weak.
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Eshan Arora
8thAbout Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
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Ayan Ghosh
8thMy experience with Abhyas academy is very good. I did not think that my every subject coming here will be so strong. The main thing is that the online tests had made me learn here more things.
Hiya Gupta
8thAbhyas Methodology is very good. It is based on according to student and each child manages accordingly to its properly. Methodology has improved the abilities of students to shine them in future.
Manish Kumar
10thIt has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
