<u>Ionic Bond</u> is formed when the electronegativity difference is 0.4 > 2.0. Electronegativity is a term that can be defined as a tendency of an atom to attract electron towards its own self.
Explanation:
Electronegativity is a term that can be defined as a tendency of an atom to attract electron towards its own self.
An electronegativity of an atom is affected by
- The atomic number of the atom
- Secondly by the distance at which the valence electron are residing from the nucleus
1. In case the electronegativity difference (which is denoted by ΔEN) is less than 0.5 then the bond formed is known as N<u>onpolar covalent.
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2. In case the ΔEN is in between 0.5 and 1.6, the bond formed is referred to as the<u> Polar covalent
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3. In case the ΔEN is more /greater than 2.0, then the bond formed is referred to as<u> Ionic Bond</u>
<u>2 Examples of Ionic bonds</u>
- The formation of sodium fluoride, NaF, from a sodium atom and a fluorine atom is an example of Ionic bond formation.
- Another example is the formation of NaCl from sodium (Na),which is a metal, and chloride (Cl), which is a nonmetal
Elements of Group 1 and group 2 in the periodic
table contain elements so reactive that they are never found in the free state
<u>Explanation</u>:
The metals in group 1 of periodic table consisting of 'alkali metals' which include lithium, potassium, sodium, rubidium, Francium and caesium. They are highly reactive because they have low ionisation energy and larger radius. The group 2 metals consist of 'alkaline earth metals' which include calcium, strontium, barium, beryllium, radium and magnesium. These alkaline earth metal have +2 oxidation number, hence are highly reactive.
These both group metals are mostly reactive and so are never found in a free state. When they are exposed to air they would immediately react with oxygen. Hence, are stored in oils to avoid oxidation.
Answer: The ion that contribute to water hardness are:
--> a. Ca2+
--> b. (HCO)3^- and
--> c. Mg2+
While K+ DOES NOT contribute to water hardness.
Explanation:
WATER in chemistry is known as a universal solvent. This is so because it is polar in nature and dissolves most inorganic solutes and some polar organic solutes to form aqueous solutions. It is composed of elements such as hydrogen and oxygen in the combined ratio of 2:1.
Water is said to be HARD if it does not lather readily with soap. There are two types of water hardness:
--> Permanent hardness: This is mainly due to the presence of CALCIUM and MAGNESIUM ions in the form of soluble tetraoxosulphate(VI) and chlorides. These ions are removed by adding washing soda or caustic soda.
--> Temporary hardness: This is due to the presence of calcium HYDROGENTRIOXOCARBONATES. It can be removed by boiling and using slaked lime.
Therefore from the above given ions, Ca2+,(HCO)3^- and Mg2+ contributes to water hardness.
Answer:
Answers are given below
Explanation:
(a) Aldehyde groups are reduced by sodium borohydride in methanol to give alcohol.
So, butanal produces butanol on reaction with sodium borohydride in methanol.
(b) Aldehyde forms cyanohydrin when they are treated with HCN with catalytic cyanide.
(c) Aldehydes are oxidized by potassium dichromate in dil. sulphuric acid to produce carboxylic acid.
(d) Aldehyde produces acetal with methanol and a trace amount of acid catalyst.
(e) Aldehyde gives condensation reaction with 
to produce imine.
Structures of products for the given reaction has been shown below.
