Explain in detail about Secondary Bonds?

Secondary Bonds

Today we will see the second kind of bond that is present which are known as the secondary bonds. Secondary bonds are relatively weak bonds when compared to primary bonds and they are also known as Van der Walls bond much weaker than chemical bond. Because there is no actual exchange of electrons or sharing of electrons. But as we will see there is a dipole induced or existing in the natural state and that dipole produces electrical attraction whereby the bond exists that is the nature of the secondary bonds. This exists between almost all atoms in one form or other. But they are hard to detect because the primary bond present is much more stronger than the secondary bond. They are formed due to electrical dipole either because of charge separation or because of Anathem inherent polarity in the atom. The resultant force is coulombic attraction since there is charge separation, there is columbic attraction and that is what causes the secondary bond. 

Dipole Interaction

Now the dipole interaction occurs in three forms, that is the secondary bonds can occur in three forms. Prominently one is induced dipoles that he is a both the atoms which are part of the secondary bond has induced dipole. The second possibility is one polar molecule and thus dipole and finally two polar molecules. Hydrogen bond is a special case of secondary bonds and that occurs when one of the participating molecule has something like hydrogen there by the name hydrogen. Hydrogen is specifically highly electro positive and it has at the other end the molecule. Fluorine like if you have hydrogen fluoride then hydrogen is highly electro positive and it develops a slight positive charge and fluorine slides negative charge. Therefore the adjacent hydrogen fluorine will also develop positive and negative charge. This is inherently because of the high electro positivity of hydrogen. There by a bond which is known as hydrogen bond is created. 

Induced Dipole

Now let us discuss all the three step by step to begin with induced dipoles that is induced out dipole. Induced dipole kind of secondary bond any atom as such is mainly symmetric atom and symmetric atoms has symmetric charge distribution. Thereby they do not have any disparity of charge throughout the atom. There is a positive charge here due to the protons and the negative electron revolves around it symmetrically. But what happens is that the symmetry of the atom is broken and there is fluctuating dipoles created in momentarily bases and that is shown here. 

So symmetric atom momentarily transforms to an induced dipole. Now what is happening here we can see is that the positive charge is coming off center here and negative charge is coming this way. So effectively we have a plus over here and a minus here. Our dipole is created now this momentary creation of dipole will induce a dipole in the adjacent molecule too. So if there was a atom or molecule over here which was symmetric but now due to this it will be similar. Distortion will occur and the positive this place will become positive again and this end will become negative and this induced dipole. Induced dipole combination produces interaction. This interaction is a secondary bond known as induced dipole-induced dipole interaction. The constant vibration causes instantaneous distortion in the atom or molecule. 

As  in a small electric dipole beam being created and this small dipole induces polarity in the adjacent atoms or molecules. Similarly this induced dipole will affect its adjacent atoms and molecules. Hence a whole chain of induced dipole is created, thereby the different atoms at practice other. So this is what is the induced dipole kind of secondary bonding and as we can see that the induced dipole. The induced polarity in the atoms is quite weak because this is just due to the asymmetry of the distribution of electrons with respect to the nucleus. Therefore the strength of the force that is this attractive force is very weak in nature. This is in fact thus weakest secondary force amongst the three second forces because both are induced and that this results in a very low bond energy and such compounds or such atoms has a very less melting point. 

Polar Molecule

Now let us jump into the second kind of secondary bond which is polar molecule induced dipole. A polar molecule is inherently a symmetric electric distribution. It has inherent a symmetric electric distribution there. Why it is inherently has a dipole in it and such molecules are known as polar molecules. Now what happens is since it has inherent polarity in it that will induce dipole in the adjacent atoms which are inherently not a symmetric rather symmetric. But the polar molecule will induce electrical charge asymmetry momentarily and will lead to again interaction and attraction between the polar molecule. The induced dipole and this phenomena will extend throughout the material. Thereby a weak bond is created which is secondary in nature. But this weak bond is stronger than the induced dipole. Induced dipole kind because this has a permanent symmetric distribution in the form of a polar molecule. The polar molecule has a permanent dipole moment this induces a dipole moment in other electrically symmetric atom or molecule and attractive force develops. As a result this is stronger than the induced dipole case. 

Now after this let's go to the third kind in which both the molecules or the atoms which we are talking are inherently asymmetric that is both are polar molecules. So we have a polar molecule scenario whereby attractive force between two molar polar molecules and the force is stronger than the previous two configuration obviously. Because both molecules are polar that is there is no need to induce any charge distribution. They are inherently as symmetrically just distributed. Initially there is a special case known as hydrogen bonding and the example which we discussed is hydrogen fluoride. Hydrogen is slightly positively charged fluorine. Hydrogen fluoride slightly positive slightly negative charged this is a polar molecule. 

Another hydrogen fluoride this is also a polar molecule and they attract each other forming a hydrogen bond which is a special kind of polar molecule. Polar molecule attraction hydrogen series. It's only electron strong positive and very strong attraction between fluorine of hydrogen fluoride which is negative of this. Now among the three different kinds of secondary bonding this polar molecule is the strongest kind of secondary bonding. Thereby it has the molecules which manifest itself in polar molecule. Polar molecule secondary bonding has the highest melting point and even in this case even in the polar molecule polar molecule keys. The hydrogen bonding elements which has rather the molecules, which has hydrogen bonding are the strongest kind of bond. 

Today we saw the different kinds of secondary bonding which are not chemical bonding because there is no sharing or transfer of electrons. Rather there is creation of a charge distribution which is asymmetric either inherently or induced and that leads to or like here in hydrogen fluoride. The molecules attract each other by this kind of bonding also hydrogen bonding can be seen in hydrogen chloride. Basically hydrogen bonding too should have a high electronegativity difference with hydrogen. 

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