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प्रश्न
Find the odd man out:
पर्याय
Tinning
Anodization
Alloying
Froth floatation
उत्तर
Froth floatation
APPEARS IN
संबंधित प्रश्न
Write two methods of preventing the rusting of iron.
Give reasons:
Platinum, gold and silver are used to make jewellery.
Two methods by which rusting of iron can be prevented are ______ and ______.
Explain how painting of an iron gate prevents it from rusting.
Explain why rusting of iron objects is faster in coastal areas than in deserts.
Write a chemical equation to show the process of corrosion of iron.
Name the metal which is used for galvanising iron.
Fill in the following blank with suitable word:
The corrosion of iron is called ................
Why is an iron grill painted frequently?
Name any two metals which do not corrode easily.
What is meant by 'rusting of iron'? With the help of labelled diagrams, describe an activity to find out the conditions under which iron rusts.
Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.
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.
(a) What could the solids A and B be?
(b) What are the products C and D most likely to be?
(c) 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.
(d) What is the special name of such a reaction? State one use of such a reaction.
(e) Name any two types of chemical reactions under which the above reaction can be classified.
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.
Bronze is an alloy of ______.
Explain how the activity series accounts for each of the following:
tendency to corrosion
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
What are the adverse effects of corrosion?
Explain the term – rusting and give a word equation for the formation of rust. If polished iron nails are kept in three separate test tubes, state the contents in each test tube required, to prove the conditions for rusting.
State whether the statement given below is true or false. If false write the correct statement.
Graphite is a lustrous non-metal which conducts electricity.
Observe the following picture and answer the following questions:
- What is rust?
- Write the chemical formula of rust.
- Write the reaction of oxidation of iron at the anode.
- Write the reaction of oxidation of iron at the cathode.
- What is corrosion?
Pressure cooker : Anodizing : : Silver plated spoons : _______
Find the odd one out and give its explanation.
Write the name.
Method used to prevent corrosion of copper.
What is rust?
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?
State two conditions necessary for rusting of iron.
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?
State whether the following statements are true or false:
Ships suffer a lot of damage though they are painted.
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
Explain the chemical reactions in rusting of iron.
