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प्रश्न
Write the molecular formulae of the following compound.
Fluorspar
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उत्तर
Fluorspar- CaF2
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संबंधित प्रश्न
Write the composition of the alloy called bronze.
Name one metal which is extracted by reduction with heat alone.
Why does aluminium not corrode right through?
Name two metals which occur in nature in free state as well as in combined state.
Name one ore of sodium. Name the sodium 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.
State why aluminium is extracted from its oxide by electrolysis while copper, lead, iron by reducing agents and mercury and silver by thermal decomposition.
Give the chemical formula of :
Sodium aluminate
What is passive iron?
The following questions relate to the extraction of aluminium by electrolysis.
Explain why it is necessary to renew the anode periodically.
Complete the incomplete statement with missing word:
Non-metals form acidic oxides while metals form ______.
Carbon cannot reduce the oxides of sodium, magnesium, and aluminum to their respective metals. Why? Where are these metals placed in the reactivity series? How are these metals obtained from their ores? Take an example to explain the process of extraction along with chemical equations.
Iron is _______.
Aluminium oxide is _______ oxide.
Atomic number of aluminium is _______ and its electronic configuration is _______.
_______ is the least reactive metal.
Complete flow chart given below.
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?
Which of the following ore is concentrated by the Froth floatation process?
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.
