1.2 Structure of Water and H Bonding
Water (H2O) is made up of two hydrogen atoms covalently bound to an oxygen atom. While this bonding involves the sharing of electrons, they are not shared equally. The oxygen atom, having more protons (+ve), attract the electrons (-ve) more strongly (i.e. the oxygen has a higher electronegativity). Thus the oxygen atom becomes slightly negative and the hydrogen atoms become slightly positive
To Think About:
What is the chemical structure of water? How does the chemical structure of water result in polarity? How does water’s polarity result in cohesion and adhesion through hydrogen bonding interactions? What chemical characteristics of water result from its cohesive and adhesive properties? How do living systems depend on the chemical properties of water?
Watch: AP Daily Video Structure of Water and Hydrogen Bonding
Answer the Following Questions:
- Explain why water is a polar molecule.
- Define a hydrogen bond.
- Draw the hydrogen bonding between two adjacent water molecules.
- Explain the difference between cohesion and adhesion.
- Define each of the following properties of water, and explain why each is a result of water’s ability to form hydrogen bonds: Surface tension, High solvency, Ice floats, High heat capacity
Supplementary Resources:
- Bozeman Science: Mr. Andersen’s “Water: A Polar Molecule” video
- Amoeba Sisters: Properties of Water
- Crash Course Biology: Water—Liquid Awesome
Khan Academy: The Properties of Water
BioNinja: Chemical Elements and Water
