Alloy Formation

Q. A Metal m crystallizes in fcc & bcc structure depending upon the temperature .The ratio of its densities in fcc&bcc would be

Q. What raw materials are required for steel making?

Q.

Name the substance formed on surface of copper when it reacts with moist carbon dioxide in air write the equation also.

Q.

The heating element of an electric iron is made up of

1. copper

2. nichrome

3. aluminum

4. iron

Q. A tarnished copper vessel begins to shine again when rubbed with lemon . justify the statement

Q.

Though zinc is more reactive than iron, yet it prevents rusting. Justify.

Q.

Write equations for the reactions of:
1. Iron with steam.
2. Calcium with water.
3. Potassium with water. [3 MARKS]

Q. Which of the following alloy is used in aircraft?

1. Duralumin
2. Sterling silver
3. Gunmetal
4. German silver

Q.

The metals tin and zinc are present in the alloy

1. duralumin

2. Solder

3. bronze

4. brass

Q.

Why are school bells made up of metal?

Q.

Give an example of metal which is brittle?

Q.

The alloy of which of the following metals, is usually used for making bells?

1. Iron (Fe)

2. Lead (Pb)

3. Copper (Cu)

4. Aluminium (Al)

Q.

The incorrect statement is

1. Cast iron is used to manufacture wrought iron.

2. Brass is an alloy of copper and nickel.

3. German silver is an alloy of zinc, copper, and nickel.

4. Bronze is an alloy of copper and tin

Q.

Does vinegar dissolve Aluminum?

Q.

Brass is an alloy of copper and tin, which is used in electrical fillings and decorative items.

1. True

2. False

Q.

Find the mass of lead formed by the reduction of 342.5 g of red lead($P{b}_3{O}_4$) in a current of hydrogen.

1. 210.5 g

2. 310.5 g

3. 250 g

4. 377.79 g

Q.

Bronze is a mixture of 10% copper, 80% zinc and 10% tin

1. True
2. False

Q. If zinc coating is removed after galvanisation, the iron article does not corrode. Why.

Q. State the main components of the duralumin.

Q. Bronze is an alloy containing 10% copper, 80% zinc and 10% tin.

1. True
2. False

Q.

Name the following

An alloy of Lead and Tin that is used in electric circuits

Q.

Aluminium is silvery white lustrous___. (metal/non-metal)

Q.

Which of the following is/are an alloy of Aluminium?

1. Duralumin

2. Magnalium

3. Alnico

4. All of these

Q.

State a reason why zinc is used in:

(a) galvanisation, (b) dry cells, (c) cosmetics?

Q.

Calculate the percentage of nitrogen in aluminium nitride. [A1 = 27, N = 14]

1. 44.10%

2. 30.14%

3. 34.14 %

4. 20.22%

5. 24.10%

6. 40.22%

Q.

Galvanization is a process in which metal (Iron or steel) is __________.

1. Coating with alloy.

2. Coating with metal oxide.

3. Coating with zinc.

4. Coating with metallic paint.

Q.

Why do ionic compound have high melting point

Which metal do not corrode easily

What are alloys

Q. What is an alloy give examples with diagrams

Q.

The process of converting vegetable oils into fats in the presence of nickel as catalyst is called

1. hydrogenation.

2. alloying.

3. rusting.

4. galvanization.

Q.

The ‘green rust’ of copper is scrapped and dissolved in water. When litmus paper is dipped in it, what will be the change in colour ?

1. Red to blue

2. Purple to red

3. blue to green

4. Green to purple