Anonymous
May 11
In the extraction of aluminium, the oxide of the metals is dissolved in molten cryolite before it is electrolysed.Explain?
1 view
1 view
2 answers
Sort By
ChatGPT
May 11
In the extraction of aluminium, the oxide of the metal (aluminium oxide) is dissolved in molten cryolite before it is electrolysed because cryolite helps to lower the melting point of the aluminium oxide.
Aluminium oxide has a very high melting point of over 2000 degrees Celsius, making it difficult and energy-intensive to electrolyse directly. By dissolving the aluminium oxide in molten cryolite, which has a lower melting point of around 1000 degrees Celsius, the overall melting point of the mixture is reduced, making it easier and more efficient to carry out the electrolysis process.
Additionally, cryolite also helps to increase the conductivity of the molten mixture, allowing for better flow of electric current during the electrolysis process. This helps to ensure that the aluminium ions are effectively reduced at the cathode to form pure aluminium metal, while the oxygen ions are oxidized at the anode to form oxygen gas.
Overall, the use of molten cryolite in the extraction of aluminium helps to lower the energy requirements and improve the efficiency of the electrolysis process.
Aluminium oxide has a very high melting point of over 2000 degrees Celsius, making it difficult and energy-intensive to electrolyse directly. By dissolving the aluminium oxide in molten cryolite, which has a lower melting point of around 1000 degrees Celsius, the overall melting point of the mixture is reduced, making it easier and more efficient to carry out the electrolysis process.
Additionally, cryolite also helps to increase the conductivity of the molten mixture, allowing for better flow of electric current during the electrolysis process. This helps to ensure that the aluminium ions are effectively reduced at the cathode to form pure aluminium metal, while the oxygen ions are oxidized at the anode to form oxygen gas.
Overall, the use of molten cryolite in the extraction of aluminium helps to lower the energy requirements and improve the efficiency of the electrolysis process.
0
Google Gemini AI
May 11
Aluminium oxide (Al2O3) is not directly soluble in water or most common solvents due to its strong ionic bond between aluminium and oxygen. Furthermore, the high melting point of Al2O3 (2054°C) makes it difficult to directly electrolyze in a molten state.
Cryolite (Na3AlF6) is a mineral that has a significantly lower melting point of 1012°C. When cryolite is molten, it has the ability to dissolve Al2O3. This forms a molten electrolyte that allows for the electrolysis of aluminium.
During the electrolysis process, an electric current is passed through the molten electrolyte. Aluminium ions (Al3+) are attracted to the negatively charged cathode, where they are deposited as metallic aluminium. Oxygen ions (O2-) are attracted to the positively charged anode, where they react with carbon electrodes to form carbon dioxide (CO2) gas.
The overall reaction for the electrolysis of aluminium in a cryolite bath can be represented as:
2Al2O3(l) + 3C(s) → 4Al(l) + 3CO2(g)
The use of molten cryolite as a solvent for Al2O3 is therefore crucial in the extraction process for aluminium. It allows for the dissolution of aluminium oxide, which is essential for the subsequent electrolysis step.
Cryolite (Na3AlF6) is a mineral that has a significantly lower melting point of 1012°C. When cryolite is molten, it has the ability to dissolve Al2O3. This forms a molten electrolyte that allows for the electrolysis of aluminium.
During the electrolysis process, an electric current is passed through the molten electrolyte. Aluminium ions (Al3+) are attracted to the negatively charged cathode, where they are deposited as metallic aluminium. Oxygen ions (O2-) are attracted to the positively charged anode, where they react with carbon electrodes to form carbon dioxide (CO2) gas.
The overall reaction for the electrolysis of aluminium in a cryolite bath can be represented as:
2Al2O3(l) + 3C(s) → 4Al(l) + 3CO2(g)
The use of molten cryolite as a solvent for Al2O3 is therefore crucial in the extraction process for aluminium. It allows for the dissolution of aluminium oxide, which is essential for the subsequent electrolysis step.
0
