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प्रश्न
Find the odd one out and give its explanation.
पर्याय
Brass
Bronze
Phosphorous
Steel
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उत्तर
Phosphorous
Explanation-
Phosphorus is nonmetal while others are alloys.
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संबंधित प्रश्न
Give two examples of alloys with their chemical composition.
Explain the term corrosion.
Which of the following methods is suitable for preventing an iron frying pan from rusting?
Explain why rusting of iron objects is faster in coastal areas than in deserts.
Explain why Iron sheets are coated with zinc during galvanization.
Name the metal which is used for galvanising iron.
Give the constituents of brass.
Name an alloy of copper. State its chemical composition and any one use.
Explain why, when a copper object remains in damp air for a considerable time, a green coating is formed on its surface. What is this process known as?
Name a common metal which is highly resistant to corrosion.
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.
Explain how the activity series accounts for each of the following:
tendency to corrosion
Compare roasting and calcination.
Complete the process of iron rusting by filling the blanks. Suggest a way to prohibit the process.
The iron rust is formed due to........................... reaction. Different
regions on iron surface become anode and cathode.
Reaction on anode region :
`F_e(s) → Fe^(2+) (aq) +2e^-`
Reaction on anode region :
`O_2(g) + 4H^+(aq) +............................ → 2H_2 O (l) `
When Fe2+ ions migrate from anode region they react with ................... to form Fe3+ ions.
A reddish coloured hydrated oxide is formed from ............... ions. It is called rust.
`2Fe_(3+) (aq) + 4H_2O(l) → ................. + 6H_+(aq) `
A way to prevent rusting ..................................................................
Answer the following question.
a) What is meant by corrosion?
b) Write names of any two methods of prevention of corrosion.
c) In which method, metal like copper, aluminium are coated with a thin layer of their oxides by means of electrolysis.
d) Explain this method with diagram.
What is done to prevent corrosion of metals?
What is ‘rusting’?
Answer the following question.
List two properties of alloys.
Give reason.
A wooden article should be polished.
Give reason.
Copper and brass utensils should be tinned.
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 _______.
Find the odd one out and give its explanation.
Write the name.
An alloy of copper and tin-
Write the name.
Method used to present corrosion of copper.
Write scientific reason.
On exposure to air, silver articles turn blackish after some time.
Write scientific reason.
Coins are made from metals and alloys.
Give solutions by giving examples of corrosion?
The process of coating the surface of the metal with a thin layer of zinc is called ______
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:
Identify the correct statement from the following:
Iron pillar near the Qutub Minar in Delhi is famous for the following facts. Which of these facts is responsible for its long stability?
Give an example of a chemical reaction for the following situation:
Sound is produced
Gold plated ornaments is the example of ______.
Give scientific reasons.
Silver amalgam is used for filling dental cavities.
