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प्रश्न
In ______ process a layer of molten tin is deposited on metals.
पर्याय
Anodization
Tinning
Galvanizing
Alloying
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उत्तर
In tinning process a layer of molten tin is deposited on metals.
Explanation:
A greenish layer forms on the surface of a copper or brass vessel. This greenish layer is poisonous. If buttermilk or curry is placed in such a vessel, it gets spoiled. Tinning is done to prevent all such damages.
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संबंधित प्रश्न
What is an alloy?
Which metals do not corrode easily?
Give reasons:
Platinum, gold and silver are used to make jewellery.
What is anodising? Give its applications.
What type of chemical reaction is involved in the corrosion of iron?
Name any three objects (or structures) which are gradually damaged by the corrosion of iron and steel.
What is meant by galvanisation? Why is it done?
Name the metal which is used for galvanising iron.
In one method of rust prevention, the iron is not coated with anything. Which is this method?
The process of depositing a thin layer of zinc on iron articles is called ______.
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What are the constituents of stainless steel?
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- Which of the two metals is more reactive: X or Y?
- Name one ore or metal X. Also write its chemical formula.
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- Name one alloy of metal X and one alloy of metal Y.
Mention two uses of the following metals and non-metals
Iron
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Identify the process shown in the diagram and explain it in short
Answer the following question:
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Write three methods of preventing rusting of iron.
Answer the following question.
List two properties of alloys.
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Either oxygen or moisture is essential for rusting.
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Write the name.
An alloy of copper and tin-
Draw a neat labelled diagram.
Anodizing
Complete flow chart given below.
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Observe the following diagram and write answers.
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- Explain the method.
- Give two examples of this method.
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| 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 |
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Give scientific reasons.
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| A process of forming a thick oxide of aluminium when aluminium is exposed to air. This coat makes it resistant to corrosion. Resistance can be improved by making a layer of oxide thinker. In this technique, the aluminium article is the anode, and the electrolyte is sulphuric acid. The anode reaction results in the formation of a black-coloured film of aluminium oxide on the anode. By putting appropriate dyes in the electrolytic solution, both coloured surface with the decorative finish is achieved. Kitchen articles like anodised such as pressure cookers, pans and frames of sliding windows are applications of this technique. |
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Describe two changes that are harmful. Explain why you consider them harmful. How can you prevent them?
