English

Explain how painting of an iron gate prevents it from rusting.

Advertisements
Advertisements

Questions

Explain how painting of an iron gate prevents it from rusting.

How does the painting of an iron object prevent its rusting?

Short/Brief Note
Advertisements

Solution 1

Moisture (water) and air (oxygen) aid rusting. By painting an iron gate, we prevent its contact with the air and moisture present in the atmosphere.

shaalaa.com

Solution 2

  • The regular method used to prevent rusting of iron objects is painting the surfaces of iron objects. Rusting takes place in the presence of both air and water.
  • Thus, when a layer of paint is applied to the surface of an iron object, it prevents the contact of air and moisture with the iron surface and avoids the rusting of iron objects.
shaalaa.com
  Is there an error in this question or solution?
Chapter 5: Physical and Chemical Changes - Exercises [Page 55]

APPEARS IN

NCERT Science [English] Class 7
Chapter 5 Physical and Chemical Changes
Exercises | Q 9. | Page 55

RELATED QUESTIONS

In one method of rust prevention, the iron is not coated with anything. Which is this method?


Fill in the following blanks with suitable words:
............ and .............. are necessary for the rusting of iron.


Name two metals which resist corrosion due to the formation of a thin, hard and impervious layer of oxide on their surface.


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.


No chemical reaction takes place when granules of a 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.

(i) Based on the given information make an assumption about A and B and write a chemical equation for the chemical reaction indicating the conditions of reaction, physical state of reactants and products and thermal status of reaction.

(ii) Mention any two types of reactions under which above chemical reaction can be classified.


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.


Pressure cooker : Anodizing : : Silver plated spoons : _______


Write the name.

An alloy of copper and tin-


Write scientific reason.

Coins are made from metals and alloys.


Write a molecular formula for rust.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×