Question

36. Describe the general trends in the following properties of the element in Group 13 and 14.
(a) Atomic size (b) ionisation enthalpy (c) Metallic character (d) oxidation states (e) nature of halides​

Answer 1

Answer:

Explanation:

(i) Group 13 has a greater atomic size as when going down a group, the atomic size increases, so an extra shell with electrons is added, and the poor shielding effect is observed.

Group14- These have a covalent radius, and a small radius is observed, and the presence of the shielding effect is high as there are completely filled d and f orbitals.

(ii) The ionization enthalpy is unaffected by the group, and it decreases with increase in size. Group 13 has erratic ionization enthalpy as the nuclear charge is complemented by the screening effect.  

Group 14 experiences a high ionization enthalpy, and it subsequently decreases and due to the poor shielding effect.

(iii) All elements in group 13 are non-metallic except Boron, and the shielding effect is responsible for the low metallic character.  

Group 14 has Sn and Pb as metals and the metallic character increases on going down the group, so the carbon is classified as a non-metal and all others are metalloids

(iv) Group 13 has prevalent +3 oxidation states due to the lone pairs but slowly change to +1 as the group order persist  

Group14 has + 4, and +2 oxidation states and the enthalpies are high, and they are covalent in nature.

(v)Group 13 forms trihalides and some electron acceptors act as Lewis Acids.  

Group 14 forms Halides by accepting electrons or sharing, making them covalent compounds.