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प्रश्न
Write a short note on Alloying.
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उत्तर
- The homogenous mixture formed by mixing metal with other metals or nonmetals in a certain proportion is called an alloy.
- Majority of the metallic substances used presently are in the form of alloys. The main intention behind this is to decrease the intensity of corrosion of metals.
- For example, bronze is an alloy formed from 90% copper and 10% tin. Bronze statues do not get affected by the sun and rain. Stainless steel does not get stains with air or water and also does not rust. It is an alloy made from 74% iron, 18% chromium and 8% carbon.
- In recent times various types of alloys are used for minting coins.
APPEARS IN
संबंधित प्रश्न
What is an alloy?
Explain the term corrosion.
Which metals do not corrode easily?
What are alloys?
What is anodising? Give its applications.
The chemical reaction involved in the corrosion of iron metal is that of ______.
What is meant by galvanisation? Why is it done?
Explain why, though aluminium is more reactive than iron, yet there is less corrosion of aluminium when both are exposed to air.
What is corrosion?
Name any two metals which do not corrode easily.
What is the corrosion of iron known as?
Name an alloy of copper. State its chemical composition and any one use.
Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.
If copper is kept exposed to damp air for a considerable time, it gets a green coating on its surface. This is due to the formation of ______.
Mention two uses of the following metals and non-metals
Iron
Bronze is an alloy of ______.
Explain with reason:
Roasting is carried out on sulphide ores and not on carbonate ores.
No chemical reaction takes place when granules of a 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.
(i) Based on the given information make an assumption about A and B and write a chemical equation for the chemical reaction indicating the conditions of reaction, physical state of reactants and products and thermal status of reaction.
(ii) Mention any two types of reactions under which above chemical reaction can be classified.
Observe the following picture a write down the chemical reaction with the explanation.
Answer the following question.
a) What is meant by corrosion?
b) Write names of any two methods of prevention of corrosion.
c) In which method, metal like copper, aluminium are coated with a thin layer of their oxides by means of electrolysis.
d) Explain this method with diagram.
Find the odd man out:
Give a reason why rust turns moist red litmus blue.
Find the odd one out and give its explanation.
Write the name.
An alloy of copper and tin-
Write scientific reason.
Anodization method is useful for prevention of the corrosion of the aluminium.
Explain concept with example/explain with the help of a balanced equation.
Corrosion
Draw a neat labelled diagram.
Electrolysis
What is rust?
Give solutions by giving examples of corrosion?
State two conditions necessary for rusting of iron.
Galvanisation is a method of protecting iron from rusting by coating it with a thin layer of ____________.
Copper objects lose their shine and form green coating of ____________.
The table shown below gives information about four substances: A, B, C and D.
| SUBSTANCE | MELTING POINT (K) | ELECTRICAL CONDUCTIVITY | |
| SOLID | LIQUID/ AQUEOUS | ||
| A | 295 | Good | Good |
| B | 1210 | Poor | Good |
| C | 1890 | Poor | Good |
| D | 1160 | Poor | Poor |
Identify Ionic compounds from the above given substances.
Identify the correct statement from the following:
State whether the following statement is true or false:
Ships suffer a lot of damage though they are painted.
