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प्रश्न
Write the name.
The molecular formula of main ore of aluminium –
उत्तर
The molecular formula of main ore of aluminium – Al2O3•nH2O
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संबंधित प्रश्न
In the extraction of aluminium Write the cathode reaction in electrolytic reduction of alumina.
How many carats is pure gold? Why is pure gold not suitable for making ornaments?
Explain giving one example, how highly reactive metals (which are high up in the reactivity series) are extracted.
Name one ore of aluminium. Name the aluminium compound present in this ore and write its chemical formula.
Name one ore of mercury. Which mercury compound is present in this ore? Write its chemical formula.
Give reasons, why aluminum is used in:
making alloys
Give the chemical formula of :
Cryolite
Complete the incomplete statement with missing word:
Metals form positive ions while non- metals ______.
Complete the incomplete statement with missing word:
Non-metals form acidic oxides while metals form ______.
State the property of the metal being utilized in the following :
| Use of metal | Property |
| Zinc in Galvanization | |
| Aluminium in Thermite welding |
choose the most appropriate term to match the given description.
Heating of the ore in the absence of air to high temperature
In electrolytic reduction of alumina _______ is used as a cathode.
Find the odd one out and give its explanation.
Explain the following reaction with the balanced equation.
Zinc sulphide is heated strongly in excess of air
The highly reactive metals like Sodium, Potassium, Magnesium, etc. are extracted by the ____________.
In thermite welding a mixture of ____________ is ignited with a burning magnesium ribbon which produces molten iron metal as a large amount of heat is evolved.
Why should the metal sulphides and carbonates be converted to metal oxides in the process of extraction of metal from them?
Give the reaction involved during extraction of zinc from its ore by
- roasting of zinc ore
- calcination of zinc ore
On the basis of reactivity metals are grouped into three categories:
- Metals of low reactivity
- Metals of medium reactivity
- Metals of high reactivity
Therefore metals are extracted in pure form from their ores on the basis of their chemical properties.
Metals of high reactivity are extracted from their ores by electrolysis of the molten ore.
Metals of low reactivity are extracted from their sulphide ores, which are converted into their oxides. The oxides of these metals are reduced to metals by simple heating.
(a) Name the process of reduction used for a metal that gives vigorous reaction with air and water both.
(b) Carbon cannot be used as a reducing agent to obtain aluminium from its oxide? Why?
(c) Describe briefly the method to obtain mercury from cinnabar. Write the chemical equation for the reactions involved in the process.
OR
(c) Differentiate between roasting and calcination giving chemical equation for each.
