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प्रश्न
Extraction of moderately reactive elements is done by _______ and _______ method.
विकल्प
roasting and calcination
roasting and reduction
separation and calcination
none of these
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उत्तर
Extraction of moderately reactive elements is done by roasting and calcination method.
संबंधित प्रश्न
Name the following:
Main ore of aluminium.
M is a metal above hydrogen in the activity series and its oxide has the formula M2O. This oxide when dissolved in water forms the corresponding hydroxide which is a good conductor of electricity. In the above context, answer the following:
1) What kind of combination exists between M and O?
2)How many electrons are there in the outermost shell of M?
3) Name the group to which M belongs.
4) State the reaction taking place at the cathode.
5) Name the product at the anode.
Fill in the following blank with suitable word:
The non-metal present in steel is ............
How are the less reactive metals (which are quite low in the reactivity series) extracted? Explain with the help of an example.
Name the chemical compound which is electrolysed in molten state to obtain sodium metal. Which gas is produced in this process?
The major ore of aluminium is known as:
(a) cinnabar
(b) calamine
(c) bauxite
(d) pyrolusite
Manganese metal is extracted from manganese dioxide by a reduction process by making use of:
(a) carbon
(b) hydrogen
(c) electrolysis
(d) aluminium
When an object made of metal A is kept in air for a considerable time, it loses its shine and becomes almost black due to the formation of a layer of substance B. When an object made of another metal C is kept in damp air for a considerable time, it gets covered with a green layer of substance D. Metal A is the best conductor of electricity whereas metal C is the next best conductor of electricity.
(a) What is metal A?
(b) What is metal C?
(c) Name the substance B.
(d) Name the substance D.
Some metallic oxides can be reduced by hydrogen, carbon and carbon monoxide and some cannot. Explain.
Aluminum is used in thermite welding:
what is thermit?
Give the chemical formula of :
Cryolite
Define the term:
Flux
Which one of the following is not true of metal :
Metals are malleable and ductile
Aluminium oxide is _______ oxide.
Explain the following reaction with the balanced equation.
Zinc sulphide is heated strongly in excess of air
Explain concept with example/explain with the help of a balanced equation.
Ionic bond and ionic compounds
Observe the figure and answer the following.
- Write the name of the method.
- What is used as anode and cathode in this method?
- Write the molecular formula and use of cryolite.
- Write anode reaction.
- Write cathode reaction.
The process in which a carbonate ore is heated strongly in the absence of air to convert it into metal oxide is called ____________.
A mineral from which the metal can be extracted economically and conveniently is known as ______.
