Which of the following is closest to the bond energy per mole required to break all the O=O bonds in molecular oxygen (O_2)?

• A. 146 kJ/mol
• B. 213 kJ/mol
• C. 945 kJ/mol
• D. 498 kJ/mol

Answer: (D)

Verified step by step guidance

1. Understand that the bond energy per mole is the amount of energy required to break one mole of a specific type of bond—in this case, the double bond in molecular oxygen (O_2).
2. Recall or look up the typical bond dissociation energy for the O=O double bond in O_2, which is a known standard value in chemistry reference tables.
3. Note that the bond energy for O=O is usually given in units of kJ/mol, representing the energy needed to break all O=O bonds in one mole of O_2 molecules.
4. Compare the given options to the known bond energy value for the O=O bond, which is approximately 498 kJ/mol, to identify the closest match.
5. Select the value closest to the known bond energy for O=O, understanding that this value reflects the strength of the double bond in molecular oxygen.