Rank the following from Longest to Shortest bond length:
i) H-F
ii) As-As
iii) NC
iv) O=O
v) Cl-Cl
This should get you started. The longest bond lengths form the weakest bonds; stronger bonds are shorter.
http://www.science.uwaterloo.ca/~cchieh/cact/c120/bondel.html
To rank the given bonds from longest to shortest, we need to consider the molecular geometries and the bond types associated with each bond.
i) H-F: This is a covalent bond between hydrogen (H) and fluorine (F). Fluorine is more electronegative than hydrogen, so it attracts the bonding electrons more strongly. Therefore, H-F bond is short and strong.
ii) As-As: This is a covalent bond between two arsenic (As) atoms. Arsenic is a large atom, and the electron-electron repulsion between the bonding electrons causes an increase in bond length compared to a single As-As bond.
iii) NC: This refers to a triple bond between nitrogen (N) and carbon (C) atoms. Triple bonds are generally shorter than double bonds, and double bonds are shorter than single bonds. Therefore, the NC bond is shorter in length.
iv) O=O: This is a double bond between two oxygen (O) atoms. Double bonds are shorter than single bonds due to increased electron density between the bonded atoms.
v) Cl-Cl: This is a single bond between two chlorine (Cl) atoms. Since this is a bond between two similar atoms, there is no significant difference in electronegativity, resulting in a longer bond length.
Based on this analysis, we can arrange the bonds from longest to shortest as follows:
v) Cl-Cl > ii) As-As > i) H-F > iv) O=O > iii) NC