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प्रश्न
When one of the metals in an alloy is mercury the alloy is called _______.
पर्याय
amalgam
sodium amalgam
zinc amalgam
all the above
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उत्तर
When one of the metals in an alloy is mercury the alloy is called amalgam.
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संबंधित प्रश्न
Write two methods of preventing the rusting of iron.
Why do we apply paint on iron articles?
Explain the term corrosion.
Explain why rusting of iron objects is faster in coastal areas than in deserts.
Choose the correct answer from the options given below:
Heating an ore in a limited supply of air or in the absence of air at a temperature just below its melting point is known as
A. Smelting
B. Ore-dressing
C. Calcination
D. Bessemerisation
Explain why, though aluminium is more reactive than iron, yet there is less corrosion of aluminium when both are exposed to air.
What are the special properties of stainless steel?
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.
Name the metal which is a constituent of plant pigment?
What is corrosion? What are necessary conditions for corrosion?
Observe the following picture a write down the chemical reaction with the explanation.
Find the odd man out:
What is done to prevent corrosion of metals?
Choose the correct alternative and rewrite the following:
Iron is _____________________.
What is ‘rusting’?
Answer the following question.
List two properties of alloys.
Give reason.
A wooden article should be polished.
_______ forms a green colour in the water.
Stainless steel is an alloy of _______.
Bronze : _______ : : Stainless steel : Fe + Cr + C
Find the odd one out and give its explanation.
Write the name.
An alloy of copper and tin-
Write scientific reason.
On exposure to air, silver articles turn blackish after some time.
Draw a neat labelled diagram.
Anodizing
Give preventive methods by giving examples of corrosion?
What is rust?
Galvanisation is a method of protecting iron from rusting by coating it with a thin layer of ____________.
Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.
The substance not likely to contain CaCO3 is:
A man painted his main gate made up of iron, to
- prevent it from rusting.
- protect it from sun.
- make it look beautiful.
- make it dust free.
Which of the above statement(s) is/are correct?
Iron pillar near the Qutub Minar in Delhi is famous for the following facts. Which of these facts is responsible for its long stability?
State whether the following statement is true or false:
Ships suffer a lot of damage though they are painted.
Give an example of a chemical reaction for the following situation:
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.
