Advertisements
Advertisements
Question
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.
Advertisements
Solution
Electrolytic reduction of Alumina :
APPEARS IN
RELATED QUESTIONS
In the extraction of aluminium: Name the process of concentration of bauxite.
Describe with one example, how moderately reactive metals (which are in the middle of reactivity series) are extracted.
Explain how, mercury is extracted from its sulphide ore (cinnabar). Give equations of the reactions involved.
Which metal is extracted from calamine ore?
An ore of manganese metal is ______.
Calamine ore can be used to extract one of the following metals. This metal is:
The metal which can be extracted simply by heating the cinnabar ore in air is ______.
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?
Which metal can be extracted from the following ore?
bauxite
Give the principles of electromagnetic separation.
Give reasons, why aluminum is used in:
making alloys
Aluminum is used in thermite welding:
write reaction for process?
What is galvanized iron.
Extraction of moderately reactive elements is done by _______ and _______ method.
Explain Bayer’s process.
Explain the following reaction with the balanced equation.
Chlorine dissolved in water
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?
Give the reaction involved during extraction of zinc from its ore by
- roasting of zinc ore
- calcination of zinc ore
Two ores A and B were taken. On heating ore A gives CO2 whereas, ore B gives SO2. What steps will you take to convert them into metals?
The given reaction shows one of the processes to extract the metals like Iron and Manganese.
\[\ce{MnO2(s) + Al(s) -> Mn(l) + Al2O3(s) + Heat}\]
Identify the substance oxidised and reduced in the above reaction.
