Prevention of Corrosion

Q.

Methods for prevention of corrosion

Q.

What protects the underground pipe or tank from corrosion?

Q.

List some methods for the prevention of corrosion?

Q.

When Zn piece is kept in CuSO₄ solution, the copper get precipitated because standard potential of zinc is

[CPMT 1999]

1. < sulphate

2. > copper

3. < copper

4. > sulphate

Q.

1. Silver oxide, ($A{g}_{2}O$)
2. Silver chloride, ($AgCl$)
3. Silver sulphide, ($A{g}_{2}S$)
4. Silver iodide, ($AgI$)

Q. explain the chemical reactivity of alkali metals in s block element?

Q.

Why Iron sheets are treated with hydrochloric acid before galvanizing.

Q.

How can corrosion of metals be prevented?

Q.

Corrosion can be prevented by :

1. painting the metal surface
2. to prevent the contact of the metal surface with good electrical conducting media
3. alloying the metal with more anodic metal
4. all

Q. $HCl$ can be used to remove rust from iron.

1. True
2. False

Q. What is E1; Sn1 ;Sn2; E2 mechanism?

Q.

Match the statements in Column A with those in Column II.

Column 1	Column 2
A mixture of oxygen and carbon dioxide used for artificial respiration	Manganese dioxide
A compound which on strong heating yields oxygen gas.	Sodium
The process of coating zinc on the surface of iron to prevent rusting.	Carbogen
A catalyst used in laboratory preparation of oxygen from hydrogen peroxide	Potassium nitrate
A metal which burns a golden yellow flame in oxygen	Galvanising

Q. ntIf Zinc is placed above Iron in the reactivity series of metals. Then, why doesnt the zinc coating on an iron object react and corrode faster than an iron object without any zinc coating ?n

Q. Is tin more reactive than zinc?

Q. Element present in the stainless steel is ______________.

1. Chromium
2. Iron
3. Nickel
4. All of these

Q.

Which method is used to prevent rusting of automobile parts (Car radiators)?

1. Use of anti rust solution

2. Galvanization

3. Painting

4. Oiling and greasing

Q. 18. Give the mechanism of rusting 1. 4 2. 6 3. 8 4. 12 which option is correct and why ?

Q.

Several blocks of Mg are fixed to the bottom of a ship to:

1. prevent puncturing by under sea rocks

2. prevent action of water and salt

3. keep away the sharks

4. make the ship lighter

Q. If a piece of iron gains 10% of its mass due to partial rusting into ferric oxide the percentage of total iron that has rusted is

Q. What are the ions present in compounds $N{a}_{2}O$ and $MgO$?

Q. The main component of bronze is:

1. cobalt
2. copper
3. aluminium
4. tin

Q. Assertion :Polished iron nails do not rust when kept immersed in a test tube containing boil water covered with a layer of oil. Reason: Rust formation can be controlled with coatings such as paint or varnish that isolate the iron from environment. When only temporary protection is needed for storage or transport a thin layer of oil, grease can be applied to an iron surface.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Galvanised ion sheets are coated with

1. C
2. Cu
3. Zn
4. Ni

Q. Which of the following methods cannot be employed in order to prevent corrosion?

1. Covering the surface by paint
2. Covering the surface by some chemical
3. Allowing the surface to interact with moisture
4. Providing the sacrificial electrode of another metal

Q.

Which transition metal is known as Wonder metal?

1. Platinum
2. Iron
3. Tungsten
4. Titanium

Q. Red lead used as primer for iron to prevent it from rusting is :

1. $P{b}_3{O}_4$
2. $PbO$
3. $Pb{O}_2$
4. $P{b}_{2}O$

Q. Write the names of the metals used as sacrificial electrode for the prevention of corrosion of iron metal and how it prevents the corrosion?

Q. Pieces of copper, silver and gold are dropped into a solution of iron sulphate. The piece that will get a coating of copper is:

1. iron
2. silver
3. gold
4. None of them

Q. Various methods are adopted for protecting iron from rust. Which of the following statements is false?

1. Chrome plating looks good
2. Ordinary tin plating is cheap but not reliable
3. Zinc plating is more permanent than chrome plating
4. Zinc protects iron but does not protect itself

Q.

Painting of the Iron surface is a type of:

1. Sacrificial protection

2. Electrical protection

3. None of these

4. Barrier protection