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प्रश्न
In electrolytic reduction of alumina _______ is used as a cathode.
पर्याय
sulphur
graphite
platinum
aluminium
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उत्तर
In electrolytic reduction of alumina graphite is used as a cathode.
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संबंधित प्रश्न
Name the following:
Main ore of aluminium.
Give reasons.
Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
M is a metal above hydrogen in the activity series and its oxide has the formula M2O. This oxide when dissolved in water forms the corresponding hydroxide which is a good conductor of electricity. In the above context, answer the following:
1) What kind of combination exists between M and O?
2)How many electrons are there in the outermost shell of M?
3) Name the group to which M belongs.
4) State the reaction taking place at the cathode.
5) Name the product at the anode.
Silver metal does not combine easily with oxygen but silver jewellery tarnishes after some time. How?
What iron compound is present in haematite ore? Also write its chemical formula.
An ore of manganese metal is:
(a) bauxite
(b) haematite
(c) cuprite
(d) pyrolusite
Calamine ore can be used to extract one of the following metals. This metal is:
(a) copper
(b) mercury
(c) aluminium
(d) zinc
Give reasons, why aluminum is used in:
painting electric and telegraphic poles
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.
Answer the following questions based on the extraction of aluminium from alumina by Hall - Heroult’s Process :
Name the electrode, from which aluminium collected.
Name the following:
The process of heating a substance very strongly in such a way that it does not combine with oxygen.
How an ore is concentrated by froth floatation process?
Name:
The allotrope of the non-metal carbon which conducts electricity.
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 ______.
Compare the properties of a typical metal and a non- metal on the basis of the following:
(a) electronic configuration
(b) nature of oxides
(c) oxidizing or reducing action
(d) conductivity of heat and electricity
Define calcination.
Usually ______ ores are subjected to ______ which is done in the absence of air.
Explain the concept of Calcination.
Explain the following reaction with the balanced equation.
Zinc oxide is treated with carbon
Iqbal treated a lustrous, divalent element M with sodium hydroxide. He observed the formation of bubbles in reaction mixture. He made the same observations when this element was treated with hydrochloric acid. Suggest how can he identify the produced gas. Write chemical equations for both the reactions.
