Advertisements
Advertisements
प्रश्न
Extraction of moderately reactive elements is done by _______ and _______ method.
विकल्प
roasting and calcination
roasting and reduction
separation and calcination
none of these
Advertisements
उत्तर
Extraction of moderately reactive elements is done by roasting and calcination method.
संबंधित प्रश्न
Why does a new aluminium vessel lose shine so soon after use?
How is manganese extracted from manganese dioxide, MnO2? Explain with the help of an equation.
Name the method by which aluminium metal is extracted.
Name one ore of copper (other than cuprite). Which compound of copper is present in this ore? Also, write its chemical formula.
The metal which can be extracted from the bauxite ore is:
(a) Na
(b) Mn
(c) Al
(d) Hg
Which of the following pair of metals exists in their native state in nature?
(a) Ag and Hg
(b) Ag and Zn
(c) Au and Hg
(d) Au and Ag
Some metallic oxides can be reduced by hydrogen, carbon and carbon monoxide and some cannot. Explain.
Distinguish between ‘roasting’ and ‘calcination’. Which of these two is used for sulphide ores and why?
Define the following term.
Mineral
What is meant by refining of metals? Name the three common methods used for refining.
How many valence electrons are present in non- metals?
Which one of the following is not true of metal :
Metals are good conductors of electricity.
Heating an ore in a limited supply of air or in the absence of air at a temperature just below its melting point is known as ______.
State three objectives achieved during the roasting of ores.
Sulphide ores : Roasting : : Carbonate ores : _______
Write the name.
Metals which are amphoteric in nature.
In the electrolytic reduction of alumina, the lining of graphite acts as an anode.
Explain in brief types of extraction of less reactive metals according to their reactivity.
Iqbal treated a lustrous, divalent element M with sodium hydroxide. He observed the formation of bubbles in reaction mixture. He made the same observations when this element was treated with hydrochloric acid. Suggest how can he identify the produced gas. Write chemical equations for both the reactions.
A mineral from which the metal can be extracted economically and conveniently is known as ______.
