Advertisements
Advertisements
प्रश्न
Bauxite reacts with sodium hydroxide in the Bayer’s process.
पर्याय
Right
Wrong
Advertisements
उत्तर
Bauxite reacts with sodium hydroxide in the Bayer’s process- Right
APPEARS IN
संबंधित प्रश्न
In the extraction of aluminium: Draw the diagram for the extraction of aluminium.
A zinc ore gave CO2 on treatment with a dilute acid. Identify the ore and write its chemical formula.
How many carats is pure gold? Why is pure gold not suitable for making ornaments?
Name two metals which occur in nature in free state as well as in combined state.
Name the gas produced when calamine ore is calcined.
Which of the following metals can be obtained from haematite ore?
A metal which exists as a liquid at room temperature is obtained by heating its sulphide ore in the presence of air.
- Name the metal and write its chemical symbol.
- Write the name and formula of the sulphide ore.
- Give the equations of chemical reactions involved in the production of metal from its sulphide ore.
- Name a common device in which this metal is used.
- Can this metal displace copper from copper sulphate solution? Why?
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.
- What is metal А?
- What is metal C?
- Name the substance B.
- Name the substance D.
- What type of chemical can be used to remove the green layer from metal C and clean it? Why?
State why aluminium is extracted from its oxide by electrolysis while copper, lead, iron by reducing agents and mercury and silver by thermal decomposition.
What is meant by refining of metals?
Which method of refining is used to get 99.8% pure aluminium?
Complete the incomplete statement with missing word:
Metals are malleable while non-metals are ______.
Complete the incomplete statement with missing word:
Non-metals form acidic oxides while metals form ______.
Which one of the following is not true of metal :
Metals are good conductors of electricity.
Which one of the following is not true of metal :
Metal will have 1 or 2 or 3 electrons in their valence shell.
Sulphide ores : Roasting : : Carbonate ores : _______
Write the name.
Strongly heating carbonate ores in insufficient air -
Right or wrong sentence?
The electrolysis of alumina combines fluorite and cryolite to increase the solubility in the precipitation method.
Explain the characteristics of ionic compounds.
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.
