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प्रश्न
Write the name.
An alloy of copper and tin-
उत्तर
An alloy of copper and tin- Bronze
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संबंधित प्रश्न
Why do we apply paint on iron articles?
Explain why rusting of iron objects is faster in coastal areas than in deserts.
Explain why Iron sheets are coated with zinc during galvanization.
What special name is given to their corrosion of iron?
Fill in the following blanks with suitable words:
Tiffin boxes are electroplated with .............. but car bumpers are electroplated with ............... to protect them from rusting.
Fill in the following blank with suitable word:
The corrosion of copper produces a .............. coating of basic copper carbonate on its surface
Explain why, through aluminium is more reactive than iron, yet there is less corrosion of aluminium when both are exposed to air.
What is corrosion?
What are the constituents of stainless steel?
Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.
Name a common metal which is highly resistant to corrosion.
Brass is an alloy of:
(a) Cu and Sn
(b) Cu and Pb
(c) Pb and Sn
(d) Zn and Cu
Four metals P, Q, R and S are all obtained by the reduction of their oxides with carbon. Metal P is used to form a thin layer over the sheets of metal S to prevent its corrosion. Metal Q is used for electroplating tiffin boxes made of metal S whereas metal R is used in making car batteries. Metals Q and R form an alloy called solder. What are metals P, Q, R and S? How have you arrived at this conclusion?
Mention two uses of the following metals and non-metals
Iron
State under what conditions corrosion is faster ?
Explain with reason:
Roasting is carried out on sulphide ores and not on carbonate ores.
Observe the following picture a write down the chemical reaction with the explanation.
Identify the process shown in the diagram and explain it in short
Find the odd man out:
Answer the following question:
What is corrosion? Do gold ornaments corrode? Justify.
Write three methods of preventing rusting of iron.
Give reason.
An iron article should be given a coat of paint
_______ is an alloy made from iron, carbon and chromium.
Which of the following method is used to prevent the accumulation of greenish layer on brass due to corrosion?
Pressure cooker : Anodizing : : Silver plated spoons : _______
Rusting of iron : Fe2O3 : : corrosion of copper : ______
Write the name.
Method used to prevent corrosion of copper.
Write scientific reason.
Coins are made from metals and alloys.
Explain concept with example/explain with the help of a balanced equation.
Corrosion
Draw a neat labelled diagram.
Anodizing
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 diagram and write answers.
- Name the method.
- Explain the method.
- Give two examples of 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 the equation for the formation of rust.
Galvanisation is a method of protecting iron from rusting by coating it with a thin layer of ____________.
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.
Explain the following:
Lime water turns milky on passing carbon dioxide gas into it.
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.
