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प्रश्न
Name two metals which resist corrosion due to the formation of a thin, hard and impervious layer of oxide on their surface.
उत्तर
Aluminium and zinc are two metals that resist corrosion due to the formation of a thin, hard and impervious layer of oxide on their surface. Aluminium and zinc form tough layers of aluminium oxide and zinc oxide by reacting with air.
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संबंधित प्रश्न
Give two examples of alloys with their chemical composition.
Which of the following methods is suitable for preventing an iron frying pan from rusting?
What is anodising? Give its applications.
The chemical reaction involved in the corrosion of iron metal is that of:
(a) oxidation as well as displacement
(b) reduction as well as combination
(c) oxidation as well as combination
(d) reduction as well as displacement
Explain why, iron sheets are coated with zinc.
Fill in the following blank with suitable word:
The corrosion of iron is called ................
Fill in the following blanks with suitable words:
Tiffin boxes are electroplated with .............. but car bumpers are electroplated with ............... to protect them from rusting.
Why is an iron grill painted frequently?
What is corrosion?
Name any two metals which do not corrode easily.
Give the constituents and one use of brass.
Explain why, when a copper object remains in damp air for a considerable time, a green coating is formed on its surface. What is this process known as?
Identify the process shown in the diagram and explain it in short
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 molecular formula for rust.
Generally, when metals are treated with mineral acids, hydrogen gas is liberated but when metals (except Mn and Mg), treated with HNO3, hydrogen is not liberated, why?
Give an example of a chemical reaction for each of the following situations:
Sound is produced
| 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.
In ______ process a layer of molten tin is deposited on metals.
