Question

Without using Fig. 13.3, predict which bond in each of the following groups is the most polar.

(a) C-F, Si-F, Ge-F

(b) P-Cl, S-Cl

(c) S-F, S-Cl, S-Br

(d) Ti-Cl, Si-Cl, Ge-Cl

(e) C-H, Si-H, Sn-H

(f) Al-Br, Ga-Br, In-Br, Tl-Brb.

Short answer

Answer:

(a)C-F is most polar.

(b)P-F is more polar.

(c) S-F is most polar.

(d) Ti-Cl is the most polar among them.

(e) C-H is most polar.

(f) Al-Br is most polar.

Step-by-step solution

Identifying the group or period of different elements.

Electronegativity is the tendency of the element to pull the electron cloud towards them. If the dipole moment of a compound is zero i.e compound is nonpolar. If the dipole moment of a compound is not zero therefore, the compound is polar.

We know that among the group electronegativity decreases down and in a period, it increases.

(a) C-F, Si-F, Ge-F

These elements are from the 14 th group. Since, down the group ∆EN decreases.Therefore C-F is most polar.

Identifying whether ∆EN is increasing or decreasing. Then polarity.

(b) P-F, S-F

Elements are from the same period. Since, ∆ENincreases in period. Therefore, P-F is more polar.

Identifying which bond is more polar among P-F, S-F

(c)S-F, S-Cl, S-Br

Elements are from the same group. ∆EN decreases down the group. Therefore, polarity decreases,S-F is most polar.

Identifying which bond is most polar among S-F, S-Cl, S-Br

(d) Ti-Cl,Si-Cl, Ge-Cl

Here, Ti and Ge are of the same period and Si and Ge from the same group. Ti-Cl is the mostpolar among them.

Identifying which bond is most polar among Ti-Cl, Si-Cl, Ge-Cl

(e) C-H, Si-Cl,Sn-H

Elements are from the same group. ∆EN decreases,polarity decreases. C-H is most polar.

(f)Al-Br, Ga-Br, In-Br, Tl-Br

Elements are from the same group. ∆EN decreases,polarity decreases. Al-Br is most polar.