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प्रश्न
Aluminium oxide is _______ oxide.
पर्याय
acidic
basic
neutral
amphoteric
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उत्तर
Aluminium oxide is amphoteric oxide.
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संबंधित प्रश्न
Name two metals which are found in nature in the free state.
Define the term mineral.
Which gas is produced during the extraction of aluminium? At which electrode is this gas produced?
Which metal is extracted from bauxite ore?
Which of the following is an iron ore?
(a) cinnabar
(b) calamine
(c) haematite
(d) rock salt
Calamine ore can be used to extract one of the following metals. This metal is:
(a) copper
(b) mercury
(c) aluminium
(d) zinc
Which of the following metals can be obtained from haematite ore?
(a) copper
(b) sodium
(c) zinc
(d) iron
Rock salt is an ore of one of the following metals. This metal is:
(a) Mn
(b) Na
(c) Fe
(d) Cu
Which metal can be extracted from the following ore?
Haematite
Name the following:
The mixture of materials fed into a furnace to extract a metal.
How an ore is concentrated by froth floatation process?
How are metals refined by the electrolytic methods?
What is passive iron?
X is an element in the form of a powder. X burns in oxygen and the product is soluble in water. The solution is tested with litmus. Write down only the word which will correctly complete each of the following sentences:
(a) If X is a metal, then the litmus will turn ______.
(b) If X is a non-metal, then the litmus will turn ______.
(c) If X is a reactive metal, then ______ will be evolved, when X reacts with dilute sulphuric acid.
(d) If X is a non -metal, it will form _ oxide, which will form ______ solution with water.
(e) If X is a non -metal, it will not conduct electricity unless it is carbon in the form of ______.
How is the method of extraction of metals high up in the reactivity series different from that for metals in the middle? Why can the same process not be applied for them? Name the process used for the extraction of these metals.
Explain the following reaction with the balanced equation.
Ferric oxide is reacted with aluminium.
Explain the following reaction with the balanced equation.
Zinc sulphide is heated strongly in excess of air
Explain Bayer’s process of concentration of bauxite with a chemical equation.
Observe the figure and answer the following.
- Write the name of the method.
- What is used as anode and cathode in this method?
- Write the molecular formula and use of cryolite.
- Write anode reaction.
- Write cathode reaction.
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?
