Advertisements
Advertisements
प्रश्न
Define roasting.
Advertisements
उत्तर
Roasting is the process of heating concentrated ore to a high temperature in the presence of air. The process is usually carried out for sulphide ores.
संबंधित प्रश्न
Which of the following pairs will give displacement reactions?
Name the following:
The property possessed by metals by which they can be beaten into sheets.
How is copper extracted from its sulphide ore? Explain the various steps supported by chemical equations. Draw labelled diagram for the electrolytic refining of copper.
In the extraction of aluminium: Why is it necessary to replace anodes time to time?
Name a reducing agent that may be used to obtain manganese from manganese dioxide.
How is manganese extracted from manganese dioxide, MnO2? Explain with the help of an equation.
Define the term gangue.
How is copper extracted from its sulphide ore (copper glance), Cu2S? Explain with equations of the reactions involved.
Which of the following metals can be obtained from haematite ore?
Metals X and Y can be recovered from the anode mud left behind after the electrolytic refining of copper metal. The coins made of metal X look new even after several years of use but the coins made of metal Y lose their shine gradually and get blackened soon. When metal X is alloyed with a small amount of metal Y, it becomes hard and hence suitable for making ornaments. What are metals X and Y? Also state the colour of metal X.
Give reasons, why aluminum is used in:
In aluminiothermy
Identify the process given in following passage and draw neat labelled diagram showing the process.
Electrolysis of molten mixture of alumina (melting point > 20000C) is done in a steel tank. The tank has a graphite lining on the inner side. This lining does the work of a cathode. A set of graphite rods dipped in the molten electrolyte works as anode. Cryolite (Na3AlF6) and fluorspar (CaF2) are added in the mixture to lower its melting point upto 10000C.
State one observation for each of the following :
Copper sulphate solution is electrolysed using copper electrodes.
What is meant by concentration of ores?
How are metals refined by the electrolytic methods?
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
Answer the following question :
What is the difference between calcination and roasting.
Froth floatation process is generally used to concentrate ______ ores.
What is the difference between calcination and roasting?
_______ is the least reactive metal.
Identify who I am!
Ore of Aluminum- ______
Explain Bayer’s process.
Explain the characteristics of ionic compounds.
Explain in brief types of extraction of less reactive metals according to their reactivity.
In extraction of copper, the flux used is ____________.
Which of the following metals exist in their native state in nature?
- Cu
- Au
- Zn
- Ag
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?
Why should the metal sulphides and carbonates be converted to metal oxides in the process of extraction of metal from them?
