Exam 1 Review Sheet: Water Essentials and Properties

Vocabulary practice flashcards covering water essentials, molecular structure, polarity, hydrogen bonding, and its unique physical/chemical properties.

Water ($H_2O$) Earth Distribution

Water covers $75\%$ of Earth's surface, with $97.5\%$ classified as saltwater and $2.5\%$ as freshwater.

Polar Molecule

A molecule that is overall neutral in net charge but possesses localized areas of partial positive ($\delta^+$) and partial negative ($\delta^-$) charge.

Partial Charges in Water ($H_2O$)

The asymmetric charge distribution in a water molecule, featuring a partial negative charge ($\delta^-$) near the oxygen atom and partial positive charges ($\delta^+$) near the hydrogen atoms.

Intramolecular Polarity

Polarity occurring within a single water molecule resulting from the high electronegativity of oxygen compared to hydrogen.

Intermolecular Hydrogen Bonding

A weak attraction formed between distinct polar molecules or between different regions of a large polar molecule, occurring when a partially positive hydrogen atom is attracted to a strongly electronegative atom.

FON Elements

Fluorine ($F$), Oxygen ($O$), and Nitrogen ($N$); highly electronegative atoms that create functional group polarity and enable hydrogen bonding when paired with hydrogen ($H$).

Covalent Bond (in Water)

An intramolecular chemical bond formed by shared electrons between an oxygen atom and a hydrogen atom within a water molecule.

Intermolecular vs. Intramolecular Bonding in Water

A comparison showing the intramolecular covalent bond created by shared electrons within an $H_2O$ molecule versus the intermolecular hydrogen bond created by the force of attraction between positive hydrogen and negative oxygen atoms.

Water Molecule Hydrogen Bonding Network

A structural depiction showing polar covalent bonds within a central $H_2O$ molecule and surrounding hydrogen bonds connecting its partial charges ($\delta^+$ and $\delta^-$) to neighboring water molecules.

Versatile Solvent

A key property of water enabling it to dissolve polar molecules and ionic compounds due to its dipolar nature and hydrogen-bonding capabilities.

Cohesion and Adhesion

Properties of water resulting from hydrogen bonding where water molecules stick to one another (cohesion) or attach to other polar substances and surfaces (adhesion).

High Specific Heat Capacity

A thermal property of water caused by hydrogen bonding that allows it to absorb or release large quantities of heat energy with minimal changes in temperature.

High Boiling Point and Heat of Vaporization

Thermal properties of water resulting from hydrogen bonds, requiring substantial energy input to break intermolecular forces and transition liquid water into a gas.

Evaporative Coolant

A thermal management property of water where the transition of liquid water to vapor removes excess thermal energy from a surface or living organism.

High Melting Point and Heat of Fusion

Thermal properties of water describing the high energy requirement needed to disrupt its crystal lattice during the phase transition from solid ice to liquid water.

Expansion at Freezing

A structural property of water where ice forms a crystalline structure that is less dense than liquid water, allowing solid ice to float on liquid water.

Transparency of Water

An optical property of liquid water that permits visible light to pass through, enabling aquatic organisms to carry out photosynthesis below the water surface.

Biological Role in Metabolism

The functional requirement of water as a direct chemical reactant in photosynthesis and a metabolic waste product in cellular respiration.