Advertisements
Advertisements
Question
Answer the following questions based on the extraction of aluminium from alumina by Hall - Heroult’s Process :
What is the function of cryolite used along with alumina as the electrolyte?
Solution
In the extraction of aluminium, the metal is to be isolated from alumina (Al2O3) by carrying out its electrolytic reduction. The melting point of alumina veery high (2323K).
- It is therefore, mixed will cryolite ( Na2AlF6 ) which lowers its melting point to 1173 k.
- More over, cryolite also increase the electrical conductivity of alumina.
APPEARS IN
RELATED QUESTIONS
Metallic oxides of zinc, magnesium and copper were heated with the following metals.
| Metal | Zinc | Magnesium | Copper |
| Zinc oxide | – | – | – |
| Magnesium oxide | – | – | – |
| Copper oxide | – | – | – |
In which cases will you find displacement reactions taking place?
In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
A zinc ore gave CO2 on treatment with a dilute acid. Identify the ore and write its chemical formula.
Explain giving one example, how highly reactive metals (which are high up in the reactivity series) are extracted.
Explain given equation, what happens when ZnCO3 is heated in the absence of air?
Which metal is extracted from calamine ore?
Choose the correct answer from the options given below:
The metal is a liquid at room temperature.
Name the following :
The Process of heating an ore to a high temperature in the presence of air.
Explain the following reaction with the balanced equation.
Ferric oxide is reacted with aluminium.
Explain the following reaction with the balanced equation.
Dry aluminium hydroxide is ignited at 1000 °C
