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प्रश्न
In Electrolytic reduction of alumina, Anode : _______ : : Cathode : Graphite lining
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उत्तर
In Electrolytic reduction of alumina, Anode : Set of carbon (graphite) rods : : Cathode : Graphite lining
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संबंधित प्रश्न
Define the Ore.
Name two metals which are found in nature in the free state.
Give one word or a phrase:
The process by which sulphide ore is concentrated.
Explain why, carbon cannot reduce oxides of sodium or magnesium.
Why does aluminium not corrode right through?
A zinc ore on heating in air forms sulphur dioxide. Describe briefly any two stages involved in the conversion of this concentrated ore into zinc metal.
Define the term gangue.
What is the difference between a mineral and an ore?
Explain how, mercury is extracted from its sulphide ore (cinnabar). Give equations of the reactions involved.
The two metals which are extracted by means of electrolytic reduction of their molten salts are ______.
In an electrolytic tank, aluminium metal is being extracted by the electrolysis of molten aluminium oxide using carbon electrodes. It is observed that one of the carbon electrodes is gradually burnt away and has to be replaced.
- Which carbon electrode (cathode or anode) is burnt away?
- Why is this carbon electrode burnt away?
Name the following:
The substance added to get rid of gangue in the extraction of metal.
Complete the incomplete statement with missing word:
Non-metals form acidic oxides while metals form ______.
Calcium, copper, lead, aluminium, zinc, chromium, magnesium, iron.
Choose the major metals from the list given above to make the following alloys:
(a) Stainless steel
(b) brass
Name the process used for the enrichment of sulphide ore.
Write the molecular formulae of the following compound.
Fluorspar
Answer the questions on the following passage.
The minerals from which the metal can be separated economically are called ores. Ores contain many types of impurities such as soil, sand and rocky substances along with metal compounds. These impurities are called gangue.
Metals can be extracted from their ores by means of various methods of separation. The process of extraction of metal in a pure state from the ores is also a part of metallurgy.
Ores are taken out from the mines and the gangue is usually separated from the ore at the site itself by various methods. Then the ores are carried out to the place where metals are produced. Here metals are extracted in pure form. Then metals are further purified by different methods of purification. This entire process is called metallurgy. Most metals being reactive do not occur in nature in the free state but are found in combined state as their salts such as oxides, carbonates, sulphides, and nitrates. however, the most unreactive metals that are not affected by air, water and other natural factors like silver, gold, platinum, generally occur in a free state. The compounds of metals that occur in nature along with the impurities are called minerals.
- What are ores?
- Which processes are involved in the branch of metallurgy? What is metallurgy?
- Which metals are found in a free state?
- In what forms are metals found in combined state?
- What is gangue?
The process in which a carbonate ore is heated strongly in the absence of air to convert it into metal oxide is called ____________.
2 mL each of concentrated HCl, HNO3 and a mixture of concentrated HCl and concentrated HNO3 in the ratio of 3 : 1 were taken in test tubes labelled as A, B and C. A small piece of metal was put in each test tube. No change occurred in test tubes A and B but the metal got dissolved in test tube C respectively. The metal could be
An alloy is
