Predict the Order of increasing bond length for (i) H2(g) (ii) I2(g) (iii) F2(g)
I don't know how I should know
To predict the order of increasing bond length for H2(g), I2(g), and F2(g), we need to consider the size of the atoms involved and the number of electron pairs in the bonding orbital.
Generally, larger atoms have longer bond lengths due to increased atomic size. So, the bond length increases as we move down a group in the periodic table.
In this case, we are comparing hydride (H), iodine (I), and fluorine (F) molecules.
(i) Hydride (H2(g)): Hydrogen (H) atom is the smallest atom. Therefore, hydrogen molecules have the shortest bond length among the three.
(ii) Iodine (I2(g)): Iodine (I) atoms are larger compared to hydrogen. Therefore, iodine molecules have longer bond lengths than hydrogen.
(iii) Fluorine (F2(g)): Fluorine (F) atoms are the smallest atoms among the three. Therefore, fluorine molecules have shorter bond lengths than iodine.
Therefore, the predicted order of increasing bond length for the given molecules is:
H2(g) < I2(g) < F2(g)
Basically it's the size of the atom. Here is a table.
http://www.science.uwaterloo.ca/~cchieh/cact/c120/bondel.html