A1.1.2—Hydrogen bonds in water
Water molecules are polar, so partial charges attract between neighbouring molecules to form hydrogen bonds that explain water’s distinctive physical properties.
- Syllabus
- First assessment 2025
- Objective
- A1.1.2
- Level
- HL
Exam analysis
Chance of appearing8%of analysed past papers
Latest appearanceMay 2025
Most common paper—
Typical marks1–3
Common command terms
- Identify
- Describe
- Explain
- Outline
- Draw
Scoring notes
- Common mistake
- Drawing a hydrogen bond between atoms within the same water molecule.
Recent exam appearances
May 2025Paper1A HL · TZ11[ 1 ]A1.1.2—Hydrogen bonds in water
May 2024Paper2 HL · TZ16(a)[ 3 ]A1.1.2—Hydrogen bonds in water
May 2023Paper2 HL · TZ25(a)[ 2 ]A1.1.2—Hydrogen bonds in water
May 2023Paper2 HL · TZ14(b)(i)[ 2 ]A1.1.2—Hydrogen bonds in water
May 2023Paper2 HL · TZ14(a)(ii)[ 1 ]A1.1.2—Hydrogen bonds in water
Practice this objective
Coverage 2013–2025 · Updated 14 Jul 2026
Concept essentials
- Unequal electron sharing makes each O–H bond polar.
- Oxygen is partially negative and hydrogen is partially positive.
- Hydrogen bonds form between different water molecules.
- Disrupting hydrogen bonds requires energy.
- Hydrogen bonding explains important thermal properties of water.