Chapter 3: Water and Life

Vocabulary flashcards covering key terms about water's properties, acids/bases, pH, buffers, and related concepts from the notes.

Cohesion

The ability of water molecules to form hydrogen bonds with other water molecules.

Adhesion

The ability of water molecules to form hydrogen bonds with other substances.

Surface tension

How difficult it is to stretch or break the surface of a liquid.

Capillary action

Movement of water within narrow spaces or tubes due to cohesion and adhesion.

Xylem

Plant tissue in trees that pulls in water upward through narrow tubes.

Transpiration

The loss of water vapor from plant surfaces that helps drive water movement.

Specific heat

Amount of heat required to raise the temperature of 1 g of a substance by 1°C; water has a high specific heat.

Universal solvent of life

Water’s ability to dissolve many substances, making it the solvent of life.

Solvent

The substance in which a solute dissolves (water is a common solvent).

Solute

The substance dissolved in the solvent (e.g., salt in salt water).

Solution

A homogeneous mixture of solvent and solute (e.g., salt water).

Hydrophilic

Water-loving; readily dissolves in water (polar or charged).

Hydrophobic

Water-fearing; does not dissolve in water (nonpolar).

Like dissolves like

Polar substances dissolve in polar solvents and nonpolar substances dissolve in nonpolar solvents.

Hydrogen bond

A strong type of intermolecular bond between a hydrogen atom and an electronegative atom in another molecule.

Acid

A substance with higher [H+] than [OH−], increasing [H+] or decreasing [OH−].

Base

A substance with lower [H+] than [OH−], decreasing [H+] or increasing [OH−].

pH

A scale to measure acidity/basicity; pH = -log[H+], with [H+][OH−] = 10^−14 and a range of 0–14.

Buffer

Weak acids or bases that resist changes in pH; example carbonic acid.

Le Chatelier’s Principle

In chemical equilibrium, a system counteracts disturbances to re-establish equilibrium.

Proton (H+)

A hydrogen ion; a single proton.

Hydroxide ion (OH−)

An negatively charged ion that combines with H+ to form water; part of the pH balance.

Density

Mass per unit volume (Density = mass/volume); water expands as it freezes, changing density.

Density change upon freezing

Water expands when it freezes, so ice is less dense than liquid water.

Solubility

The ability of a substance to dissolve in a solvent.