1. WHY IS COPPER WIRING USED IN HOUSES ?
2. WHY IT IS POSSIBLE TO DRAW BY SILVER EVEN AN LONG POINT OF PENSIL BREAKES ?
3. WHY DOES THE COPPER UTINSIL SHINE AFTER SCRUBBING ?
4. WHAT IS CORRISION
5. GIVE2 USES OF ALLOYS

1) Why copper wiring is done in houses?

Both aluminum and copper are good electrical conductors but in houses mostly copper wiring is done because copper has high melting point and high electrical conductivity. Aluminum is not used in homes because it corrodes easily and corroded aluminum i.e. Alluminium oxide acts as an insulator.

2)Why copper utensils shine after rubbing?

When copper vessels or articles are left open in air for sometime, their surface become dull green in colour. This is because copper is corroded by the moisture and gases present in air, as a result of which a mixture of copper hydroxide and copper carbonate is formed on the surface of these objects giving them a dull green appearance. Following is the chemical equation for the reaction

2Cu + H₂O + CO₂ + O₂ →CuCO₃+ Cu(OH)₂

Both these compounds are basic in nature. Therefore, when rubbed with lemon, the citric acid present in lemon juice neutralizes these bases, forming a salt and thereby removing them from the surface. Hence, the dull surface of cooper utensils starts shining again when they are rubbed with lemon.

3) For corrosion

Kindly refer to the following link :-

https://www.meritnation.com/ask-answer/question/what-is-corrosion/chemical-reactions-and-equations/5288630

4) For uses of  alloys

Kindly refer to the following link 

https://www.meritnation.com/ask-answer/question/write-use-of-alloys-1-bell-metal-2-monel-metal-3-solder/materials-metals-and-non-metal.../2252865

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