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प्रश्न
Explain in brief types of extraction of less reactive metals according to their reactivity.
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उत्तर
Extraction of less reactive metals:
- Less reactive metals such as gold, silver, platinum are found in a free state in nature.
- However, the reserves of copper in the free state are very few. It is found mainly in the form of Cu2S. Copper is obtained from Cu2S ore just by heating in the air.
\[\ce{\underset{\text{sulphide}}{\underset{\text{Copper(I)}}{2Cu2S_{(s)}}} + \underset{\text{Oxygen}}{3O_{2(g)}} ->[Heat] \underset{\text{oxide}}{\underset{\text{Copper(I)}}{2Cu2O_{(s)}}} + \underset{\text{dioxide}}{\underset{\text{Sulphur}}{2SO2\uparrow}}}\]
\[\ce{\underset{\text{Copper(I) sulphide}}{Cu2S_{(s)}} + \underset{\text{Copper(I) oxide}}{2Cu2O_{(s)}} ->[Heat] \underset{\text{Copper}}{6Cu_{(s)}} + \underset{\text{Sulphur dioxide}}{SO_2\uparrow}}\] - The copper metal thus obtained can be further refined electrolytically.
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संबंधित प्रश्न
Name the most abundant metal in the earth's crust.
Name the gas in air which tarnishes silver articles slowly.
Why does a new aluminium vessel lose shine so soon after use?
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.
Explain giving one example, how highly reactive metals (which are high up in the reactivity series) are extracted.
How is copper extracted from its sulphide ore (copper glance), Cu2S? Explain with equations of the reactions involved.
Zinc blende ore can be converted into zinc oxide by the process of:
(a) roasting
(b) hydrogenation
(c) chlorination
(d) calcination
When an object made of metal A is kept in air for a considerable time, it loses its shine and becomes almost black due to the formation of a layer of substance B. When an object made of another metal C is kept in damp air for a considerable time, it gets covered with a green layer of substance D. Metal A is the best conductor of electricity whereas metal C is the next best conductor of electricity.
(a) What is metal A?
(b) What is metal C?
(c) Name the substance B.
(d) Name the substance D.
Give reasons, why aluminum is used in:
In aluminiothermy
Name the ore of mercury. With the help of balanced chemical equations, explain the process of extraction of mercury from its ore.
Name the following:
The mixture of materials fed into a furnace to extract a metal.
Complete the incomplete statement with missing words:
Metals are ______ while non-metals are ______ conductors of heat.
How many valence electrons are present in metals ?
Which one of the following is not true of metal :
Metals form non-polar covalent compounds
Name the following :
The Process of heating an ore to a high temperature in the presence of air.
Observe the given figure of reactivity series of metals and answer the following questions:
Reactivity series of metals
- Name two metals which react with water.
- Name two moderately reactive metals.
- Name the most highly reactive metal and the most less reactive metal.
Write the name.
The process of extraction of aluminium from alumina-
Bauxite reacts with sodium hydroxide in the Bayer’s process.
Explain the concept of Roasting.
During extraction of metals, electolytic refining is used to obtain pure metals.
(a) Which material will be used as anode and cathode for refining of silver metal by this process?
(b) Suggest a suitable electrolyte also.
(c) In this electrolytic cell, where do we get pure silver after passing electric current?
