Amazon.in Widgets ICSE CHEMISTRY - NOTES CHAPTER-WISE PRACTICE PAPERS - Revision Classes online - Call 8897306498: Metallurgy class 10 notes - ICSE CHEMISTRY

CHEMISTRY IMPORTANT NOTES For ICSE - 2023

ICSE CHEMISTRY CLASS 10 NOTES PDF FILE

ICSE CLASS 10 CHEMISTRY NOTES PDF - DOWNLOAD Download - free ICSE CLASS 10 CHEMISTRY NOTES pdf file from icsechemistry16 blog. Model papers...

Monday 22 February 2021

Metallurgy class 10 notes - ICSE CHEMISTRY

Metallurgy class 10 notes - ICSE CHEMISTRY

Metallurgy Important points for Final exam ICSE BOARD

Click here to Subscribe to ICSE CHEMISTRY for Chapter-wise Notes Practice Papers Work sheets pdf files

Notes of Metallurgy Chemistry ICSE

Mineral: Naturally occurring compounds of metals along with the earthly impurities.

Ore: The mineral from which metals are extracted easily and profitably.

Metallurgy: The process in which metals are extracted from their minerals.

Matrix (or) Gangue: The impurities that associated with an ore.

 

Metallurgy involves the following steps:

Step -I - Concentration of Ore-Removal of impurities.

Step - II - Conversion of ore to metal oxide.

Step - III - Reduction of the metal oxide to the metal.

Step - IV - Refining impure metal to pure metal.

 

 

Extraction of Aluminium from Bauxite ore:

Ore : Bauxite – Al2O3.2H2O – Hydrated Aluminium oxide

 

Step I: Concentration of ore

            The matrix is removed by chemical method.

            Chemical used : Conc. Sodium hydroxide solution

            Process name: Baeyer’s process

 

æ      Al2O3.2H2O + 2NaOH --> 2NaAlO2 + 3H2O

The amphoteric nature of Aluminium oxides makes it react with NaOH where as other impurities like Fe2O3 and SiO2 do not react and will be separated out.

           

æ      NaAlO2 + 2H2O -->  NaOH + Al(OH)3

Al(OH)3 crystals are added to the dil. NaAlO2 solution to further precipitate out Al(OH)3 crystals this process is called seeding.

 

æ      2Al(OH)3  --> Al2O3 + 3H2O

                                                      Alumina

Step II : This step is not necessary as the pure ore is an oxide.

 

Step III : Reduction of pure Alumina to Aluminium.

            Aluminium oxide (Alumina) is not reduced by reducing agents because it is highly stable hence Alumina is reduced by electrolysis in Hall Heroult’s process.


 

Hall Heroult’s process

 

Electrolyte                   : Fused mixture of Alumina (Al2O3) , Cryolite (Na3AlF6) and

                                    Fluorspar (CaF2) in the ratio 1:3:1.

Reason: Cryolite lowers the fusion point of Alumina (20500C to 9500C)and enhances the conductivity of the electrolyte.

Electrolytic cell           : Steel tank with Carbon lining acts as cathode.

Electrodes                   : Anode – A series of Graphite electrodes

                                    Cathode – The electrolytic cell with Carbon lining

Graphite rods connected in a series is taken as anode instead of one Graphite rod because the Oxygen released at anode will oxidize them to CO and CO2.

Precaution:

Coke powder is sprinkled on the surface of fused electrolyte.

Reason: It prevents the oxidation of anode by the atmospheric Oxygen and heat loss by radiation.

 

Electrolytic reaction involves the following steps:

Na3AlF6 --> 3Na+ + Al3+ + 6F

CaF2 --> Ca2+ + 2F

Al2O3 --> 2Al3+ + 3O2 –

at cathode : 2Al3+ + 6e  --> 2Al                  product: pure Aluminium metal

at anode : 6O2 – - 12e  -->  3O2                           product: Oxygen gas (CO and CO2)

HALL-HEROULT'S PROCESS


 

Step IV is not necessary because the Aluminium metal obtained in Hall Heroult’s process is 99.5% pure. (Further purification can be done by Hoope’s process.)

1 comment:

Neha kumari said...

The ICSE board is one of the most popular boards in India and students who belong to the ICSE board are very unique. Due to pandemic, many students have not concentrated on their studies. Now students are worried about their exams, so don't stress because Ziyyara is here to help you.
Visit On:- online tuition for icse
Phone no - +91-9654271931