Advertisements
Advertisements
प्रश्न
Why do we apply paint on iron articles?
Advertisements
उत्तर १
Iron articles are painted because it prevents them from rusting. When painted, the contact of iron articles with moisture and air is cut off. Hence, rusting is prevented.
उत्तर २
Iron articles are painted to prevent them from rusting. When left unpainted, the metal surface comes into contact with atmospheric oxygen, and in the presence of moisture, it becomes iron (III) oxide. But if painted, the surface does not come into contact with moisture or air, thus preventing rust.
APPEARS IN
संबंधित प्रश्न
What is an alloy?
Two methods by which rusting of iron can be prevented are ______ and ______.
Choose the correct answer from the options given below:
Heating an ore in a limited supply of air or in the absence of air at a temperature just below its melting point is known as
A. Smelting
B. Ore-dressing
C. Calcination
D. Bessemerisation
The chemical reaction involved in the corrosion of iron metal is that of:
(a) oxidation as well as displacement
(b) reduction as well as combination
(c) oxidation as well as combination
(d) reduction as well as displacement
What is meant by galvanisation? Why is it done?
Name the metal which is used for galvanising iron.
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:
Tiffin boxes are electroplated with .............. but car bumpers are electroplated with ............... to protect them from rusting.
Why is an iron grill painted frequently?
Name two metals which resist corrosion due to the formation of a thin, hard and impervious layer of oxide on their surface.
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
Name the metal which is a constituent of blood pigment?
Give reason.
An iron article should be given a coat of paint
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.
Observe the following picture and answer the following questions:
- What is rust?
- Write the chemical formula of rust.
- Write the reaction of oxidation of iron at the anode.
- Write the reaction of oxidation of iron at the cathode.
- What is corrosion?
Corrosion of silver causes a black layer of _______.
To prevent corrosion of iron and steel _______ method is used.
Bronze : _______ : : Stainless steel : Fe + Cr + C
Match the columns.
| Group A | Group B |
| 1) Electroplating | a) Pressure cooker |
| 2) Anodising | b) Silver plated spoons |
| c) Coating of tin on copper | |
| d) Coating of Zinc on iron |
Observe the following diagram and give answers.
- Name this method of prevention of corrosion.
- For prevention of which metal this method is used?
- What is used as anode in this method?
