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प्रश्न
Explain the following:
Lime water turns milky on passing carbon dioxide gas into it.
उत्तर
When carbon dioxide gas is passed through lime water, it turns milky because a white precipitate of calcium carbonate is formed.
Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water
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संबंधित प्रश्न
What is anodising? Give its applications.
What special name is given to their corrosion of iron?
Fill in the following blank with suitable word:
The process of depositing a thin layer of zinc on iron articles is called .............
Brass is an alloy of:
(a) Cu and Sn
(b) Cu and Pb
(c) Pb and Sn
(d) Zn and Cu
A metal X which is resistant to corrosion is produced by the electrolysis of its molten oxide whereas another metal Y which is also resistant to corrosion is produced by the reduction of its oxide with carbon. Metal X can be used in powder form in thermite welding whereas metal Y is used in making cathodes of ordinary dry cells.
(a) Name the metals X and Y.
(b) Which of the two metals is more reactive : X or Y?
(c) Name one ore or metal X. Also write its chemical formula.
(d) Name one ore or metal Y. Also write its chemical formula.
(e) Name one alloy of metal X and one alloy of metal Y.
Write three methods of preventing rusting of iron.
The process of coating the surface of the metal with a thin layer of zinc is called ______
Give the equation for the formation of rust.
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.
