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प्रश्न
Observe the following picture and answer the following questions:
- What is rust?
- Write the chemical formula of rust.
- Write the reaction of oxidation of iron at the anode.
- Write the reaction of oxidation of iron at the cathode.
- What is corrosion?
उत्तर
- Rust is a reddish-brown coloured hydrated ferric oxide layer deposited on the surface of iron objects that are exposed to moist air.
- Chemical formula of rust is Fe2O3.xH2O.
- Anode region: \[\ce{Fe_{(s)} -> Fe^{2+}_{ (aq)} + 2e^-}\]
- Cathode region: \[\ce{Fe^{2+}_{ (aq)} -> Fe^{3+}_{ (aq)} + e^-}\]
- Metals get attacked by substances around it such as moisture, acids, etc. Metal is said to ‘corrode’ due to this attack and the process is called corrosion.
APPEARS IN
संबंधित प्रश्न
What is an alloy?
Tinning : Tin : : Galvanizing : _________
Which metals do not corrode easily?
Which of the following methods is suitable for preventing an iron frying pan from rusting?
Explain how painting of an iron gate prevents it from rusting.
Explain why rusting of iron objects is faster in coastal areas than in deserts.
Explain why Iron sheets are coated with zinc during galvanization.
What special name is given to their corrosion of iron?
What type of chemical reaction is involved in the corrosion of iron?
Why is an iron grill painted frequently?
Name any two metals which do not corrode easily.
What is the corrosion of iron known as?
Name two metals which resist corrosion due to the formation of a thin, hard and impervious layer of oxide on their surface.
Name an alloy of copper. State its chemical composition and any one use.
A common metal which is highly resistant to corrosion is:
(a) iron
(b) copper
(c) aluminium
(d) magnesium
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.
Mention two uses of the following metals and non-metals
Iron
What is corrosion? What are necessary conditions for corrosion?
Compare roasting and calcination.
Find the odd man out:
What are the adverse effects of corrosion?
Choose the correct alternative and rewrite the following:
Iron is _____________________.
Give reason.
An iron article should be given a coat of paint
State whether the statement given below is true or false. If false write the correct statement.
Graphite is a lustrous non-metal which conducts electricity.
_______ is an alloy made from iron, carbon and chromium.
Which of the following method is used to prevent the accumulation of greenish layer on brass due to corrosion?
To prevent corrosion of iron and steel _______ method is used.
_______ forms a green colour in the water.
Bronze : _______ : : Stainless steel : Fe + Cr + C
Find the odd one out and give its explanation.
Write the name.
Method used to prevent corrosion of copper.
Write a molecular formula for rust.
Galvanisation is a method of protecting iron from rusting by coating it with a thin layer of ____________.
The iron pillar near the Qutub Minar in Delhi is famous for the following facts. Which of these facts is responsible for its long stability?
Explain the following:
Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate.
