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प्रश्न
Name an alloy of copper. State its chemical composition and any one use.
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उत्तर
An alloy of copper is bronze. The constituent elements of bronze are copper and tin. The composition of bronze is 90 percent copper and 10 percent tin. This copper alloy is very strong and corrosion-resistant.
Bronze is used in the manufacturing of statues, medals, cooking vessels, etc.
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संबंधित प्रश्न
Two methods by which rusting of iron can be prevented are ______ and ______.
Explain how painting of an iron gate prevents it from rusting.
Explain why, iron sheets are coated with zinc.
The process of depositing a thin layer of zinc on iron articles is called ______.
Name a common metal which is highly resistant to corrosion.
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.
- What could the solids A and B be?
- What are the products C and D most likely to be?
- 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.
- What is the special name of such a reaction? State one use of such a reaction.
- Name any two types of chemical reactions under which the above reaction can be classified.
Explain how the activity series accounts for each of the following:
tendency to corrosion
What is corrosion? What are necessary conditions for corrosion?
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.
Write scientific reasons.
Lemon or tamarind is used for cleaning copper vessels turned greenish.
Identify the process shown in the diagram and explain it in short
Answer the following question.
List two properties of alloys.
Corrosion of silver causes a black layer of _______.
_______ forms a green colour in the water.
Find the odd one out and give its explanation.
Write a molecular formula for rust.
The process of coating the surface of the metal with a thin layer of zinc is called ______
State two conditions necessary for rusting of iron.
Gold plated ornaments is the example of ______.
| 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. |
- Name the anode and electrolyte used in this technique.
- How can we make aluminium articles made resistant to corrosion?
- Name the technique used to coat the aluminium articles.
