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प्रश्न
What is the role of flux in metallurgical processes?
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उत्तर
The ores, even after concentration, contain some gangue. To remove gangue, certain substances are mixed with concentrated ore which combine with the gangue to form a fusible material which is not soluble in molten metal. The substances used are called fluxes.
Fluxes are classified as:
(i) Acidic flux and
(ii) Basic flux. Acidic flux removes basic impurities while basic flux removes acidic impurities.
APPEARS IN
संबंधित प्रश्न
Name the following:
An ore of zinc containing its sulphide.
The most common ore of iron is ________. (Calcium / Haematite)
Explain with reason:
Electrolytic reduction is done to obtain aluminium?
Name an alloy of aluminium used in aircraft construction.
Name an alloy of zinc used in naval ships.
Name the following:
The chief metal present in magnalium and duralumin
Define the term : Mineral
Name the process of concentration
(a) Based on densities
(b) Based on magnetic nature.
Name one metal occurring as a : Sulphide ore
Write the name and formula of two ores of the following: Iron
Write the name and formula of two ores of the following: Aluminium
What is an alloy? Give three reasons why alloys are made.
Give composition and uses of the following alloys. Mention the reason for its use.
Solder
Complete and balance the following equation:
Fe2O3 + CO →
Name an alloy of zinc which is used in simple voltaic cells.
A to F below relate to the source and extraction of either zinc or aluminium.
- Bauxite
- Coke
- Cryolite
- Froth floatation
- Sodium hydroxide solution
- Zinc blende
Write the formula of cryolite.
Find the odd one out of the following and explain your choice.
Sulphur, Phosphorous, Carbon, Iodine
| X | Y | |
| Normal Electronic Configuration | 2, 8, 7 | 2, 8, 2 |
| Nature of Oxide | Dissolves in water and truns blue litmus red. | Very low solubility in water. Dissolves in hydrochloric acid. |
| Tendency for Oxidising and reducing reactions | Tends to oxidise elements and compound. | Tends to act as a reducing agent. |
| Electrical and Thermal Conductivity | Very poor electrical conductor. Poor thermal conductivity. |
Good electrical conductor. Good thermal conductor. |
| Tendency to form Alloys and Amalgams | No tendency to form alloys. | Forms alloys. |
Using the information above, complete the following:
- _________ is the metallic element.
- Metal atoms tend to have a maximum of ________ electrons in the outermost energy level.
- Non-metallic elements tend to form _________ oxides while metals tend to form _______ oxides.
- Non-metallic elements tend to be ______ conductors of heat and electricity.
- Metals tend to _______ electrons and act as ________ agents in their reactions with elements and compounds.
The metals zinc and tin are present in the alloy
Name the processes involved in dressing of the ores.
