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प्रश्न
Explain concept with example/explain with the help of a balanced equation.
Ionic bond and ionic compounds
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उत्तर
- The compounds formed from two units, namely cation and anion are called ionic compounds.
- The cation and anion being oppositely charged, there is an electrostatic force of attraction between them. This force of attraction between cation and anion is called as the ionic bond.
- The number of cations and anions in a compound and the magnitude of the electric charge on them is such that the positive and negative charges balance each other. As a result, an ionic compound is electrically neutral.
- For example, ionic compound sodium chloride (NaCl) is formed as sodium metal gives away one electron while the nonmetal chlorine takes up one electron. Na+ and Cl− ions formed are held together by attractive force called ionic bond.
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संबंधित प्रश्न
In the extraction of aluminium: Name the process of concentration of bauxite.
Name two metals which are found in nature in the free state.
Bronze is an alloy of copper and ______.
The non-metal present in steel is ______.
Define the term ore.
Define the term gangue.
Explain giving equation, what happens when:
ZnCO3 is heated in the absence of air?
Name the chemical compound which is electrolysed in molten state to obtain aluminium metal. Which gas is evolved during this process?
In an electrolytic tank, aluminium metal is being extracted by the electrolysis of molten aluminium oxide using carbon electrodes. It is observed that one of the carbon electrodes is gradually burnt away and has to be replaced.
- Which carbon electrode (cathode or anode) is burnt away?
- Why is this carbon electrode burnt away?
State one observation for each of the following :
Copper sulphate solution is electrolysed using copper electrodes.
Give the chemical formula of :
Cryolite
Which one of the following is not true of metal :
Metals form non-polar covalent compounds
Name the methods by which concentrated ore is converted to metallic oxide.
Find the odd one out and give its explanation.
Bauxite reacts with sodium hydroxide in the Bayer’s process.
Explain the following reaction with the balanced equation.
Chlorine dissolved in water
Explain the following reaction with the balanced equation.
Zinc carbonate is heated strongly in limited supply of air
The process in which a carbonate ore is heated strongly in the absence of air to convert it into metal oxide is called ____________.
In thermite welding a mixture of ____________ is ignited with a burning magnesium ribbon which produces molten iron metal as a large amount of heat is evolved.
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.
