A triple bond is a covalent bond in which two atoms share three pairs of electrons (six electrons total), giving it the highest bond order of the three. On the AP Chem exam, that higher bond order means a shorter bond length and a larger bond energy than a single or double bond between the same atoms.
A triple bond is a covalent bond where two atoms share three electron pairs instead of one. That gives it a bond order of 3, the highest you'll see in AP Chem. Classic examples are the N≡N bond in nitrogen gas and the C≡C bond in acetylene (C₂H₂).
The AP-relevant part is what bond order does to the bond's properties. More shared electrons between the nuclei means a stronger electrostatic attraction (Coulomb's law in action), which pulls the atoms closer together. So compared to a single or double bond between the same two atoms, a triple bond is shorter and has a larger bond energy (EK 2.2.A.2). On a potential energy vs. internuclear distance graph, a triple bond shows a deeper energy well at a smaller equilibrium bond length. Deeper well, more energy required to climb out, stronger bond.
Triple bonds live in two places in the CED. In Topic 2.2 (Unit 2), learning objective 2.2.A asks you to represent the relationship between potential energy and internuclear distance. Bond order is one of the two factors (along with atomic core size) that controls bond length and bond energy, so triple bonds are the go-to example of "higher order = shorter and stronger." In Topic 6.7 (Unit 6), learning objective 6.7.A has you calculate reaction enthalpy from bond energies. Triple bonds carry big numbers (N≡N is 941 kJ/mol, C≡C is 839 kJ/mol), so whether a reaction breaks or forms a triple bond often determines whether your calculated ΔH comes out exothermic or endothermic. If you forget that combustion of acetylene breaks an 839 kJ/mol bond, your whole enthalpy answer is off.
Keep studying AP Chemistry Unit 2
Single Bond (Unit 2)
The single bond is your baseline for comparison. C-C is 348 kJ/mol while C≡C is 839 kJ/mol, but notice the triple bond is NOT three times as strong. Each additional bond adds energy, just less than the first one did. AP questions love testing whether you caught that.
Potential Energy & Internuclear Distance (Unit 2)
On a potential energy diagram, a triple bond's curve has a deeper minimum sitting at a smaller internuclear distance than a single or double bond's curve. Reading that graph (deeper well = more bond energy, well position = bond length) is exactly what LO 2.2.A asks for.
Bond Enthalpy Calculations (Unit 6)
In Topic 6.7, ΔH ≈ (energy of bonds broken) − (energy of bonds formed). Reactions that form triple bonds, like making N≡N, release a lot of energy, which is why so many nitrogen-producing reactions are strongly exothermic.
Hybridization (Unit 2)
An atom in a triple bond is sp hybridized, which gives molecules like acetylene their linear geometry with 180° angles. Triple bond questions often double as geometry questions, so know both halves.
Triple bonds show up almost entirely in multiple-choice questions that hand you data and ask you to explain it. Common stems give you bond energies (like C-C = 348, C=C = 614, C≡C = 839 kJ/mol) and ask which statement is most accurate, or ask why N≡N (941 kJ/mol) is so much stronger than O=O (495 kJ/mol) using potential energy diagrams. Another favorite asks why the C≡C bond in acetylene is shorter than the C=C bond in ethylene. The expected reasoning is always the same chain. More shared electron pairs means greater attraction between the nuclei and the electron density, which means shorter bond length and a deeper potential energy well. In Unit 6, you'll plug triple bond energies into bonds-broken-minus-bonds-formed enthalpy calculations, so don't accidentally count N≡N as three separate bonds. It's one bond with one (large) bond energy value.
Both are covalent bonds, but a single bond shares one electron pair (bond order 1) while a triple bond shares three (bond order 3). The trap is assuming the relationship is proportional. A C≡C bond (839 kJ/mol) is stronger than a C-C bond (348 kJ/mol), but not three times stronger, because each added pair of shared electrons strengthens the bond by a smaller increment. Also remember the direction of the trends. Higher bond order means MORE bond energy but LESS bond length. Students flip that constantly.
A triple bond shares three electron pairs between two atoms, giving it a bond order of 3.
Higher bond order means a shorter bond and a larger bond energy, so a triple bond is shorter and stronger than a double or single bond between the same atoms (EK 2.2.A.2).
On a potential energy vs. internuclear distance graph, a triple bond has a deeper energy well at a smaller equilibrium distance than lower-order bonds.
A triple bond is not simply three times the strength of a single bond. C-C is 348 kJ/mol and C≡C is 839 kJ/mol, less than triple.
In Topic 6.7 enthalpy calculations, treat a triple bond as one bond with one large bond energy value, like 941 kJ/mol for N≡N.
Memorize the examples N₂ (N≡N) and acetylene C₂H₂ (C≡C); they're the molecules AP questions use over and over.
A triple bond is a covalent bond where two atoms share three pairs of electrons, like the N≡N bond in nitrogen gas. It has a bond order of 3, making it shorter and stronger than single or double bonds between the same atoms.
No. C≡C is 839 kJ/mol and C-C is 348 kJ/mol, so the triple bond is stronger but well short of triple. Each additional shared electron pair adds less energy than the previous one, and AP multiple-choice questions specifically test whether you know this.
More shared electron pairs between the nuclei create a stronger attraction (Coulomb's law), pulling the atoms closer together. That's why the C≡C bond in acetylene is shorter than the C=C bond in ethylene, a comparison that appears directly in AP practice questions.
The triple bond's curve has a deeper minimum (larger bond energy) located at a smaller internuclear distance (shorter bond length). Comparing well depth and well position is exactly the skill LO 2.2.A targets.
No. Use one bond energy value for the whole triple bond, like 941 kJ/mol for N≡N or 839 kJ/mol for C≡C. Counting it as three separate single bonds is a common error that wrecks ΔH calculations in Topic 6.7.