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प्रश्न
Explain concept with example/explain with the help of a balanced equation.
Calcination
उत्तर
- The process of heating carbonate ores in limited air to convert it into respective oxide is called calcination.
- For example, zinc carbonate is heated strongly in a limited supply of air to convert it to zinc oxide.
\[\ce{\underset{\text{Zinc carbonate}}{ZnCO_{3(s)}} ->[Heat] \underset{\text{Zinc oxide}}{ZnO_{(s)}} + \underset{\text{Carbon dioxide}}{CO_2\uparrow}}\]
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संबंधित प्रश्न
In the extraction of aluminium: Name the process of concentration of bauxite.
Write the steps involved in the extraction of pure metals in the middle of the activity series from their carbonate ores.
What is meant by the 'concentration of ore'?
Which of the following is an iron ore?
(a) cinnabar
(b) calamine
(c) haematite
(d) rock salt
The major ore of aluminium is known as:
(a) cinnabar
(b) calamine
(c) bauxite
(d) pyrolusite
State three objectives achieved during the roasting of ores.
Distinguish between ‘roasting’ and ‘calcination’. Which of these two is used for sulphide ores and why?
Define the term : Slag
What is meant by concentration of ores?
Complete the incomplete statement with missing word:
Metals are malleable while non-metals are ______.
How many valence electrons are present in metals ?
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 _________
Define calcination.
Froth floatation process is generally used to concentrate ______ ores.
Write the name.
The molecular formula of main ore of aluminium –
Write the molecular formulae of the following compound.
Fluorspar
Explain the characteristics of ionic compounds.
Which of the following metals exist in their native state in nature?
- Cu
- Au
- Zn
- 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.
Care must be taken while diluting concentrated nitric acid with water. Why?
