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प्रश्न
Gold plated ornaments is the example of ______.
विकल्प
Electroplating
Alloying
Anodizing
Galvanizing
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उत्तर
Gold plated ornaments is the example of Electroplating.
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संबंधित प्रश्न
Give two examples of alloys with their chemical composition.
Explain the term corrosion.
Explain why Iron sheets are coated with zinc during galvanization.
Name any three objects (or structures) which are gradually damaged by the corrosion of iron and steel.
The chemical reaction involved in the corrosion of iron metal is that of ______.
Name the metal which is used for galvanising iron.
What is corrosion?
Name any two metals which do not corrode easily.
Name five methods of preventing rusting of iron.
Name a common metal which is highly resistant to corrosion.
A common metal which is highly resistant to corrosion is ______.
Brass is an alloy of ______.
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.
- Name the metals X and Y.
- Which of the two metals is more reactive: X or Y?
- Name one ore or metal X. Also write its chemical formula.
- Name one ore of metal Y. Also write its chemical formula.
- Name one alloy of metal X and one alloy of metal Y.
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?
Bronze is an alloy of ______.
Name the metal which is a constituent of blood pigment?
Corrosion can be an advantage in some case.Explain ?
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.
Observe the following picture a write down the chemical reaction with the explanation.
Write scientific reasons.
Lemon or tamarind is used for cleaning copper vessels turned greenish.
Answer the following question:
What is corrosion? Do gold ornaments corrode? Justify.
What is ‘rusting’?
Write a short note on Alloying.
Which of the following method is used to prevent the accumulation of greenish layer on brass due to corrosion?
Corrosion of silver causes a black layer of _______.
Pressure cooker : Anodizing : : Silver plated spoons : _______
Find the correlation:
Bronze : ______ :: Tin : Cu+Zn.
Write scientific reason.
Coins are made from metals and alloys.
Draw a neat labelled diagram.
Anodizing
What is rust?
Give the equation for the formation of rust.
Amalgam is an alloy 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.
Alloys are homogeneous mixtures of a metal with a metal or non-metal. Which among the following alloys contain non-metal as one of its constituents?
Galvanisation is a process used to prevent the rusting of which of the following?
Explain the following:
Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate.
