Which bond would be stronger? C-CL or CI C-C or C-Cl H-Cl or H-F
The Correct Answer and Explanation is :
To determine which bond is stronger among the given pairs, we need to consider bond length, bond energy, and the nature of the atoms involved. Here’s an analysis of each bond pair:
1. C–Cl vs. C–I
The bond between carbon and chlorine (C–Cl) is generally stronger than that between carbon and iodine (C–I). The bond dissociation energy (BDE) for C–Cl is about 338 kJ/mol, whereas for C–I, it is lower, approximately 285 kJ/mol. The reason for this difference lies in the size and electronegativity of the halogens. Chlorine is smaller and more electronegative than iodine, leading to a stronger overlap of orbitals in the C–Cl bond, which results in a stronger bond.
2. C–C vs. C–Cl
The C–C bond is typically stronger than the C–Cl bond. A C–C single bond has a bond energy of about 348 kJ/mol, while the C–Cl bond is weaker as mentioned above. The strong bond in C–C is attributed to effective orbital overlap between two carbon atoms, which are of similar size. In contrast, the larger size of chlorine leads to less effective orbital overlap with carbon, weakening the bond.
3. H–Cl vs. H–F
Between H–Cl and H–F, the H–F bond is stronger. The bond dissociation energy for H–F is about 567 kJ/mol, while H–Cl has a bond energy of about 431 kJ/mol. The high bond strength in H–F can be attributed to the high electronegativity of fluorine, leading to strong electron attraction and a shorter bond length compared to H–Cl. The smaller atomic radius of fluorine results in stronger overlap between the hydrogen and fluorine orbitals.
Conclusion
In summary:
- C–Cl is stronger than C–I.
- C–C is stronger than C–Cl.
- H–F is stronger than H–Cl.
The differences in bond strength arise from atomic size, electronegativity, and effective orbital overlap, with smaller and more electronegative atoms typically forming stronger bonds.