103.CHEMICAL BONDING (50)- Practice Problems.

Q:  Why is o- hydroxy benzaldehyde a liquid whereas p-hydroxy benzaldehyde a solid , with high MP, at room temperature ? A: o- hydroxy benzaldehyde has intramolecular H- bonds and so the molecules are not very tightly bound to each other as in the case of p-hydroxy benzaldehyde , where, the intermolecular H-bonds hold molecules…

102.CHEMICAL BONDING (49)- Secondary bonding(6)- Hydrogen Bonding (4)

We continue to study the physical manifestations of H- bonds and their importance. Protein folding Hydrogen bonds are an integral part of the protein structure. We will study the protein structure in detail in later posts. Here, we just need to know that proteins are made of amino acids(aa). As the name suggests, amino acids…

100.CHEMICAL BONDING (47)- Secondary bonding(4)- Hydrogen Bonding (2)

I take immense pride in writing the 100th post on this blog. I am glad that I could continue writing throughout my pregnancy, after my daughter was born and today when she is 15 months young.Looking after her single-handedly and writing was a tough task! If not for my husband, I could not have thought of continuing…

99.CHEMICAL BONDING (46)- Secondary bonding(3)- Hydrogen Bonding (1)

In this post we start discussing a type of secondary bonding, without which life would not be possible !! How is hydrogen bonding and life on earth related? Water molecule has hydrogen bonds in it.Without these bonds water would not  have the properties it possess. It would not be a universal solvent and would not…

97.CHEMICAL BONDING (44)- Secondary bonding(1)- Dipole dipole interactions.

We have already seen in post # 54 that the main difference between primary and secondary bonding is that in secondary bonding THERE IS NO SHARING OR TRANSFER OF ELECTRONS. Primary bonding Secondary bonding sharing or transfer of electrons. NO sharing or transfer of electrons. Strong force of attraction Weak force of attraction Short range Long…

96.CHEMICAL BONDING (43)- Metallic bonding(2).

As we discussed in the last post , the free electron gas model is not infallible. Almost 30 years after the electron gas model was proposed, quantum chemistry changed the perspective of looking at bonding and  thus a new approach to metallic bonding was stated. Felix Bloch graduated in Zurich, Switzerland and later went to Werner…

95.CHEMICAL BONDING (42)- Metallic bonding(1).

P3.THE METALLIC BOND. In this post we shall discuss the last kind of primary bond – The metallic bond.   We see many objects in our everyday life which are made of pure metals like gold bars/coins, copper wires etc.In all these objects the atoms of the pure element are held together by some force. How …