Advertisements
Advertisements
प्रश्न
Observe the following diagram and write answers.
- Name the method.
- Write anode reaction and cathode reaction.
- Why fluorspar and cryolite are added in the mixture?
Advertisements
उत्तर
- This method is electrolytic reduction of alumina.
- Anode reaction:
\[\ce{2O^{2-} -> O2 + 4e^-}\] (Oxidation)
Cathode reaction:
\[\ce{Al^{3+} + 3e^- -> Al_{(l)}}\] (Reduction) - Alumina has a very high melting point (>2000 °C). The purpose of mixing ‘cryolite’ and ‘fluorspar’ with ‘alumina’ in the electrolytic reduction of alumina is to carry out the process at a much lower temperature. Addition of cryolite and fluorspar reduces the melting point of alumina to about 1000 °C.
APPEARS IN
संबंधित प्रश्न
Give a reasons for the following:
Carbonate and sulphide ores are usually converted into oxides during the process of extraction of metals.
Bronze is an alloy of copper and ______.
Which one of the methods given in column I is applied for the extraction of each of the metals given in column II:
| Column I | Column II |
| Electrolytic reduction | Aluminium |
| Reduction with Carbon | Zinc |
| Reduction with Aluminium | Sodium |
| Iron | |
| Manganese | |
| Tin |
Name the chemical compound which is electrolysed in molten state to obtain aluminium metal. Which gas is evolved during this process?
What is the difference between a mineral and an ore?
An ore of manganese metal is ______.
Which of the following pair of metals exists in their native state in nature?
Which of the following reactants are used to carry out the thermite reaction required for welding the broken railway tracks?
The metal which is always present in an amalgam is ______.
Give reasons, why aluminum is used in:
wrapping chocolates
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 process in which an ore is heated in air so that oxygen gets added to it to form the oxides.
Name a non- metal that has a metallic luster and sublimes on heating.
Name the following:
The process of heating an ore to a high temperature in the presence of air.
Which one of the following is not true of metal :
Metals are good conductors of electricity.
Atomic number of aluminium is _______ and its electronic configuration is _______.
Gold and silver are active metals.
Explain the following reaction with the balanced equation.
Chlorine dissolved in water
Explain concept with example/explain with the help of a balanced equation.
Ionic bond and ionic compounds
Explain in brief types of extraction of highly reactive metals according to their reactivity.
