Which is stronger, ionic or H-bonding?

Which is stronger, ionic or H-bonding?

• A. Ionic bonding
• B. Hydrogen bonding
• C. Both are equally strong
• D. Neither

Answer: (A)

Think in terms of the energy needed to break the interaction. Ionic bonds come from full charges on ions that attract each other in a lattice, producing very high lattice energies. Hydrogen bonds are weaker electrostatic interactions between partial charges—a hydrogen attached to a highly electronegative atom and another electronegative atom with lone pairs. Because the charges are complete in ionic bonds, the energy to separate the ions is much larger than the energy to disrupt a hydrogen bond. Quantitatively, hydrogen bonds are typically in the range of about 5–30 kJ/mol, while ionic bonds in salts are hundreds of kJ/mol. So, ionic bonding is stronger overall. Even though in solution ions get solvated and this can lessen the effective strength, the intrinsic interaction strength remains greater for ionic bonds than for hydrogen bonds.

Think in terms of the energy needed to break the interaction. Ionic bonds come from full charges on ions that attract each other in a lattice, producing very high lattice energies. Hydrogen bonds are weaker electrostatic interactions between partial charges—a hydrogen attached to a highly electronegative atom and another electronegative atom with lone pairs. Because the charges are complete in ionic bonds, the energy to separate the ions is much larger than the energy to disrupt a hydrogen bond. Quantitatively, hydrogen bonds are typically in the range of about 5–30 kJ/mol, while ionic bonds in salts are hundreds of kJ/mol. So, ionic bonding is stronger overall. Even though in solution ions get solvated and this can lessen the effective strength, the intrinsic interaction strength remains greater for ionic bonds than for hydrogen bonds.