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प्रश्न
What is rust?
उत्तर
A certain type of reddish coloured solid layer collects on iron surface. This layer is called ‘rust’.
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संबंधित प्रश्न
What is an alloy?
Write two methods of preventing the rusting of iron.
Answer the following question.
What are alloys?
Write a chemical equation to show the process of corrosion of iron.
What special name is given to their corrosion of iron?
What is meant by galvanisation? Why is it done?
In one method of rust prevention, the iron is not coated with anything. Which is this method?
Why is an iron grill painted frequently?
Name any two metals which do not corrode easily.
What is meant by 'rusting of iron'? With the help of labelled diagrams, describe an activity to find out the conditions under which iron rusts.
What are the special properties of stainless steel?
What is corrosion? What are necessary conditions for corrosion?
Corrosion can be an advantage in some case.Explain ?
Identify the process shown in the diagram and explain it in short
Find the odd man out:
Give reason.
An iron article should be given a coat of paint
Give reason.
A wooden article should be polished.
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.
State whether the statement given below is true or false. If false write the correct statement.
Either oxygen or moisture is essential for rusting.
Write a short note on Alloying.
To prevent corrosion of iron and steel _______ method is used.
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.
Write scientific reason.
On exposure to air, silver articles turn blackish after some time.
Write a molecular formula for rust.
Observe the following diagram and give answers.
- Name this method of prevention of corrosion.
- For prevention of which metal this method is used?
- What is used as anode in this method?
Observe the following figure and write the answer of the question.
- Which process is shown in the figure?
- Explain the chemical reaction shown in the figure.
- Write the reactions on anode and cathode.
Give preventive methods by giving examples of corrosion?
Amalgam is an alloy of ____________.
Copper objects lose their shine and form green coating of ____________.
The diagram shows the reaction between metal and dil. acid.
What is the reason for different behaviour of Mg in test tube B?
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:
A man painted his main gate made up of iron, to
- prevent it from rusting.
- protect it from the sun.
- make it look beautiful.
- make it dust-free.
Which of the above statement(s) is/are correct?
Galvanisation is a process used to prevent the rusting of which the following?
State whether the following statements are true or false:
Ships suffer a lot of damage though they are painted.
Give scientific reasons.
Silver amalgam is used for filling dental cavities.
