Advertisements
Advertisements
Question
Define roasting.
Advertisements
Solution
Roasting is the process of heating concentrated ore to a high temperature in the presence of air. The process is usually carried out for sulphide ores.
RELATED QUESTIONS
Metallic oxides of zinc, magnesium and copper were heated with the following metals.
| Metal | Zinc | Magnesium | Copper |
| Zinc oxide | – | – | – |
| Magnesium oxide | – | – | – |
| Copper oxide | – | – | – |
In which cases will you find displacement reactions taking place?
Give a reasons for the following:
Carbonate and sulphide ores are usually converted into oxides during the process of extraction of metals.
Name two metals which are highly resistant to corrosion.
Why are the metals like Na, K, Ca and Mg never found in their free state in nature?
The non-metal present in steel is ______.
Define the term ore.
Explain giving equation, what happens when:
ZnCO3 is heated in the absence of air?
Which metal is extracted from bauxite ore?
Manganese metal is extracted from manganese dioxide by a reduction process by making use of ______.
Which of the following metals are extracted by the electrolysis of their molten chlorides?
The articles made of silver metal become dark on prolonged exposure to air. This is due to the formation of a layer of its ______.
A sulphide ore is converted into metal oxide by the process of ______.
Give the principles of electromagnetic separation.
Give reasons, why aluminum is used in:
making alloys
Give reasons, why aluminum is used in:
wrapping chocolates
Aluminum is used in thermite welding:
what is thermit?
Answer the following questions based on the extraction of aluminium from alumina by Hall - Heroult’s Process :
Name the electrode, from which aluminium collected.
Name the following:
The process in which an ore is heated in air so that oxygen gets added to it to form the oxides.
Correct the following statement :
Copper reacts with nitric acid to produce nitrogen dioxide.
Complete the following by selecting the correct option from the choices given:
The metal which does not react with water or dilute H2SO4 but reacts with concentrated H2SO4 is _________
choose the most appropriate term to match the given description.
Heating of the ore in the absence of air to high temperature
Define calcination.
Bauxite reacts with sodium hydroxide in the Bayer’s process.
Explain the following reaction with the balanced equation.
Ferric oxide is reacted with aluminium.
Explain the following reaction with the balanced equation.
Zinc oxide is treated with carbon
Explain in brief types of extraction of less reactive metals according to their reactivity.
The poorest conductor of heat among metals is ____________.
Which of the following metals exist in their native state in nature?
(i) Cu
(ii) Au
(iii) Zn
(iv) Ag
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.
Assertion (A): The extraction of metals from their sulphide ores cannot take place without roasting the ore.
Reason (R): Roasting converts sulphide ores directly into metals.
