BH3.CO in more stable than BF3.CO because:a)CO is a soft base and BH3 ...
Ans.
Hardness and Softness of an Acid and Base can be explained in terms of HSAB (Hard Soft Acid Base) theory.
According to the HSAB theory, the smaller the compound the stronger the compound, the electrons are held more tightly and are close to each other in a small molecule.
where as BH3 is soft because it is a larger compound where electrons are loosely packed, they also have low charge and are easily polarisable.
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BH3.CO in more stable than BF3.CO because:a)CO is a soft base and BH3 ...
Explanation:
Softness and hardness are terms used to describe the chemical properties of acids and bases. Soft acids have low charge density and are therefore more polarizable, while hard acids have high charge density and are less polarizable. Similarly, soft bases have lone pairs of electrons that are easily donated, while hard bases have lone pairs that are tightly held and less easily donated.
BH3 and BF3 are examples of hard acids, while CO is a soft base. This means that BH3 and BF3 have high charge density and are less polarizable, while CO has a lone pair of electrons that is easily donated. Given these properties, we can see why BH3.CO is more stable than BF3.CO.
Soft base and hard and soft acids respectively:
CO is a soft base because it has a lone pair of electrons that is easily donated. BH3 and BF3 are hard and soft acids respectively because BH3 has a high charge density and is less polarizable, while BF3 is less polarizable than BH3 due to the presence of fluorine atoms.
Soft base and hard and soft acids respectively:
When CO donates its lone pair of electrons to BH3, the resulting BH3.CO complex is stabilized by the soft-hard acid-base interaction. This is because the soft base CO interacts favorably with the hard acid BH3, resulting in a stable complex.
In contrast, when CO donates its lone pair of electrons to BF3, the resulting BF3.CO complex is destabilized by the soft-soft acid-base interaction. This is because both BF3 and CO are soft, and therefore do not interact favorably with each other. Due to this destabilization, the BF3.CO complex is less stable than the BH3.CO complex.
Conclusion:
In conclusion, BH3.CO is more stable than BF3.CO because CO is a soft base and BH3 is a hard acid, resulting in a favorable soft-hard acid-base interaction. This interaction stabilizes the BH3.CO complex and makes it more stable than the BF3.CO complex, which is destabilized by the soft-soft acid-base interaction between BF3 and CO.
BH3.CO in more stable than BF3.CO because:a)CO is a soft base and BH3 ...
It's based on HSAB principle. Soft base form stable Compound with soft acid so option A is correct.