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प्रश्न
Observe the following diagram and write answers.
- Name the method.
- Explain the method.
- Give two examples of this method.
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उत्तर
- The method is called electroplating.
- Explanation:
a. Electroplating is the process in which a less reactive metal is coated on a more reactive metal by electrolysis.
b. It protects the object made of reactive metal from corrosion. c. It also improves the appearance of the object. - Silver plated spoons, gold plated ornaments are examples of electroplating.
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संबंधित प्रश्न
Answer the following question.
What are alloys?
Give reasons:
Platinum, gold and silver are used to make jewellery.
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.
What type of chemical reaction is involved in the corrosion of iron?
Name the metal which is used for galvanising iron.
Explain why, iron sheets are coated with zinc.
State two conditions for the rusting of iron.
Fill in the following blank with suitable word:
The process of depositing a thin layer of zinc on iron articles is called .............
Why is an iron grill painted frequently?
Name any two metals which do not corrode easily.
Name an alloy of copper. State its chemical composition and any one use.
In stainless steel alloy, iron metal is mixed with:
(a) Cu and Cr
(b) Cr and Ni
(c) Cr and Sn
(d) Cu and Ni
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 plant pigment?
What is corrosion? What are necessary conditions for corrosion?
Corrosion can be an advantage in some case.Explain ?
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 ..................................................................
What are the adverse effects of corrosion?
What is "rusting"? Describe with a labelled diagram an activity to investigate the conditions under which iron rusts.
Give a reason why rust turns moist red litmus blue.
State whether the statement given below is true or false. If false write the correct statement.
Either oxygen or moisture is essential for rusting.
To prevent corrosion of iron and steel _______ method is used.
_______ forms a green colour in the water.
Find the odd one out and give its explanation.
Write the name.
Method used to prevent corrosion of copper.
Draw a neat labelled diagram.
Electroplating
Give preventive methods by giving examples of corrosion?
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:
Alloys are homogeneous mixtures of a metal with a metal or nonmetal. Which among the following alloys contain non-metal as one of its constituents?
Explain the following:
Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate.
Give an example of a chemical reaction for the following situation:
Sound is produced
