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प्रश्न
Explain the term – rusting and give a word equation for the formation of rust. If polished iron nails are kept in three separate test tubes, state the contents in each test tube required, to prove the conditions for rusting.
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उत्तर
The term Rusting involves slow oxidation of iron in presence of air and moisture which results in the formation of rust i.e. hydrated iron [III] oxide.
THE OXIDATION REACTION
Rusting of Iron
Iron + Oxygen → Iron [III] oxide Rust Hydrated iron [III] oxide
\[\ce{4Fe + 3O2 -> 2Fe2O3->[X H2O][moisture] Fe2O3.x H2O}\]
Iron when exposed to the atmosphere slowly reacts with the oxygen of the air, in the presence of moisture forming a brown coating called ‘rust’ on its surface. Rusting corrodes iron and reduces its structural strength.
APPEARS IN
संबंधित प्रश्न
Choose the correct answer from the options given below:
Heating an ore in a limited supply of air or in the absence of air at a temperature just below its melting point is known as
A. Smelting
B. Ore-dressing
C. Calcination
D. Bessemerisation
Explain why, iron sheets are coated with zinc.
Explain why, when a copper object remains in damp air for a considerable time, a green coating is formed on its surface. What is this process known as?
No chemical reaction takes place when granules of a rusty-brown solid A are mixed with the powder of another solid B. However, when the mixture is heated, a reaction takes place between its components. One of the products C is a metal and settles down in the molten state while the other product D floats over it. It was observed that the reaction is highly exothermic.
(a) What could the solids A and B be?
(b) What are the products C and D most likely to be?
(c) Write the chemical equation for the reaction between A and B leading to the formation of C and D. Mention the physical states of all the reactants and products in this equation and indicate the heat change which takes place.
(d) What is the special name of such a reaction? State one use of such a reaction.
(e) Name any two types of chemical reactions under which the above reaction can be classified.
A metal X which is resistant to corrosion is produced by the electrolysis of its molten oxide whereas another metal Y which is also resistant to corrosion is produced by the reduction of its oxide with carbon. Metal X can be used in powder form in thermite welding whereas metal Y is used in making cathodes of ordinary dry cells.
(a) Name the metals X and Y.
(b) Which of the two metals is more reactive : X or Y?
(c) Name one ore or metal X. Also write its chemical formula.
(d) Name one ore or metal Y. Also write its chemical formula.
(e) Name one alloy of metal X and one alloy of metal Y.
Find the odd one out and give its explanation.
Write the name.
An alloy of copper and tin-
Write scientific reason.
Coins are made from metals and alloys.
What is rust?
Galvanisation is a process used to prevent the rusting of which of the following?
