Why do metals need to be cleaned with sandpaper?
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Why do metals need to be cleaned with sandpaper?
Metal being reactive . When they are left in contact with air for a long time they slowly react and form oxides which gets deposited and forms a layer on it. For eg : Mg Ribbon and Iron are one of the common metals which are usually cleaned with sand paper.
How do you remove oxide layer from steel?
Because of the weak oxidising atmosphere during the process of hot rolling, a thick oxide layer is formed on the surface of stainless steel substrate, resulting in a decrease in surface quality. Thus, the oxide layer must be removed from the surface of stainless steel by pickling process.
Is it necessary to clean the zinc and copper strips or rods with sandpaper Why?
Answer: it is necessary to clean the metal strips before reaction as to remove the layer of oxides, sulphites and carbonate so that the metals becomes readily available for reaction.
Why do we rub magnesium ribbon with sandpaper?
Before burning in air, the magnesium ribbon is cleaned by rubbing with sandpaper. This is done to remove the protective layer of basic magnesium carbonate ( Mg(CO3)2) from the surface of ribbon.
Which acid is used for cleaning steel?
HCl acid
HCl acid is the most commonly used acid, and is always used for the cleaning of mild steel.
What will happen if we connect copper strip to negative terminal?
Answer: EMF of the cell increases with decrease in concentration of the electrolyte around the anode and increase in concentration of the electrolyte around cathode.
Is silver more reactive than copper?
In a reactivity series, the most reactive element is placed at the top and the least reactive element at the bottom….The reactivity series.
| Element | Reaction with dilute acids |
|---|---|
| Zinc | More slowly |
| Iron | More slowly than zinc |
| Copper | Very slowly |
| Silver | Barely reacts |
What is the dull white coating on magnesium?
oxide layer
When exposed to air many metals will slowly react with oxygen in the atmosphere to form metal oxides and magnesium is one of those metals. Like rusting in case of iron, with magnesium, the oxide layer forms a white coating on the outside of the metal that will slow down or interfere with the burning process.
Why should Mg ribbon be cleaned before burning?
Hint: Magnesium is a very reactive metal. When it is kept in the open air it can react with the gases present in the air. Cleaning will remove those impurities formed due to the reaction with air. – This high reactive nature of magnesium is the reason why magnesium ribbons should be cleaned before using it.
Can you clean metal with caustic soda?
The short answer is yes. Sodium hydroxide will not react with iron or steel, in fact the alkaline conditions will not allow rust to grow; if you make the conditions oxidizing, the black magnetic oxide will grow in its stead; hence the use of alkaline solutions of sodium nitrate for hot bluing baths.