Science, Tech, Math › Science Bond Enthalpy Definition in Chemistry Share Flipboard Email Print zhangshuang / Getty Images Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated August 08, 2019 Bond enthalpy is the enthalpy change when one mole of bonds are broken in a substance at 298 K. Bond enthalpy is also known as bond-dissociation enthalpy, bond strength, or average bond energy. The higher its value, the stronger the bond and the more energy required to break it. Typical units of bond enthalpy are kilocalories per mole (kcal/moll) and kilojoules per mole (kJ/mol). Example values in 410 kJ/mol for the C-H bond and 945 kJ/mol for the N≡N bond. From this, it's easy to see triple bonds are much stronger than single bonds. Bond enthalpy refers to the enthalpy change of one particular bond in a molecule.