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प्रश्न
A metal which exists as a liquid at room temperature is obtained by heating its sulphide ore in the presence of air.
(a) Name the metal and write its chemical symbol.
(b) Write the name and formula of the sulphide ore.
(c) Give the equations of chemical reactions involved in the production of metal from its sulphide ore.
(d) Name a common device in which this metal is used.
(e) Can this metal displace copper from copper sulphate solution? Why?
उत्तर
(a) The metal is mercury and its chemical symbol is Hg.
(b) Sulphide ore of mercury is cinnabar and its chemical formula is HgS (Mercury (II) sulphide).
(c) Mercury is a less reactive metal. Its ore cinnabar, HgS, is a sulphide ore. On heating the sulphide ore, mercury can be extracted. It is a sulphide ore; therefore, it is first heated with air (roasting process). This converts mercury (II) sulphide to mercury (II) oxide.
2HgS + 3O2 → 2HgO + 2SO2
Mercury (II) oxide, thus formed, is heated to around 300oC and it gets reduced to mercury.
2HgO → 2Hg + O2
(d) A common device wherein mercury is used is thermometer.
(e) No, mercury cannot displace copper from its salt solution. Mercury is less reactive than copper and is placed below it in the reactivity series.
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संबंधित प्रश्न
How is zinc extracted from its carbonate or (calamine)? Explain with equations.
How is aluminium metal extracted? Explain with the help of an equation.
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Cryolite
Calcium, copper, lead, aluminium, zinc, chromium, magnesium, iron.
Choose the major metals from the list given above to make the following alloys:
(a) Stainless steel
(b) brass
In electrolytic reduction of alumina _______ is used as a cathode.
Write the molecular formulae of the following compound.
Fluorspar
Explain the concept of Roasting.
Oxides of moderately reactive metals like Zinc, Iron, Nickel, Tin, Copper, etc. are reduced by using:
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.
