Question

Arrange the single covalent bonds within each set in order of increasing polarity. (a) \(\mathrm{C}-\mathrm{H}, \mathrm{O}-\mathrm{H}, \mathrm{N}-\mathrm{H}\) (b) \(\mathrm{C}-\mathrm{H}, \mathrm{B}-\mathrm{H}, \mathrm{O}-\mathrm{H}\) (c) \(\mathrm{C}-\mathrm{H}, \mathrm{C}-\mathrm{Cl}, \mathrm{C}-\mathrm{I}\) (d) \(\mathrm{C}-\mathrm{S}, \mathrm{C}-\mathrm{O}, \mathrm{C}-\mathrm{N}\) (e) \(\mathrm{C}-\mathrm{Li}, \mathrm{C}-\mathrm{B}, \mathrm{C}-\mathrm{Mg}\)

Short answer

Question: Order the following sets of covalent bonds by increasing polarity: (a) C-H, O-H, N-H (b) C-H, B-H, O-H (c) C-H, C-Cl, C-I (d) C-S, C-O, C-N (e) C-Li, C-B, C-Mg Answer: (a) C-H, N-H, O-H (b) B-H, C-H, O-H (c) C-I, C-H, C-Cl (d) C-S, C-N, C-O (e) C-B, C-Mg, C-Li

Step-by-step solution

Recall electronegativity values

We can use the following approximate electronegativity values for this exercise: C: 2.5 H: 2.2 O: 3.4 N: 3.0 B: 2.0 Cl: 3.2 I: 2.7 S: 2.6 Li: 1.0 Mg: 1.2

Calculate electronegativity differences and order the bonds

For each set of bonds, we need to calculate the electronegativity differences and then order the bonds based on these differences. (a) C-H (0.3), O-H (1.2), N-H (0.8) Ordered by increasing polarity: C-H, N-H, O-H (b) C-H (0.3), B-H (0.2), O-H (1.2) Ordered by increasing polarity: B-H, C-H, O-H (c) C-H (0.3), C-Cl (0.7), C-I (0.2) Ordered by increasing polarity: C-I, C-H, C-Cl (d) C-S (0.1), C-O (0.9), C-N (0.5) Ordered by increasing polarity: C-S, C-N, C-O (e) C-Li (1.5), C-B (0.5), C-Mg (1.3) Ordered by increasing polarity: C-B, C-Mg, C-Li