Which of the following is a typical strength (in kJ/mol) for a hydrogen bond?

• A. 20 kJ/mol
• B. 400 kJ/mol
• C. 200 kJ/mol
• D. 2 kJ/mol

Answer: (A)

Verified step by step guidance

1. Understand that hydrogen bonds are a type of intermolecular force, stronger than van der Waals forces but weaker than covalent or ionic bonds.
2. Recall typical energy ranges for different types of bonds: covalent bonds are usually hundreds of kJ/mol, while hydrogen bonds are significantly weaker.
3. Recognize that hydrogen bonds typically have bond strengths in the range of about 10 to 40 kJ/mol, which is moderate compared to covalent bonds.
4. Compare the given options (400, 200, 20, and 2 kJ/mol) to this typical range to identify the most reasonable value for a hydrogen bond strength.
5. Conclude that 20 kJ/mol fits well within the expected range for hydrogen bond strength, making it the typical value among the choices.