Chapter 1–6: Water Properties and Solutions (Vocabulary)

Vocabulary flashcards covering key concepts related to water's polarity, bonding, surface properties, heat dynamics, phase changes, and solutions.

Polar molecule

A molecule with partial positive and partial negative charges due to unequal sharing of electrons; in water, oxygen is more electronegative and bears a partial negative charge while hydrogens bear partial positive charges.

Polar covalent bond

A covalent bond in which electrons are shared unequally between atoms, leading to partial charges; in water, the O–H bonds are polar covalent.

Hydrogen bond

A weak attraction between a partially negative atom (like O) of one molecule and a partially positive hydrogen of another molecule; key in water’s properties.

Cohesion

Attraction between like molecules (e.g., water–water) due to hydrogen bonding.

Adhesion

Attraction between different substances (e.g., water sticking to plant cell walls).

Surface tension

The measure of how difficult it is to stretch or break the surface of a liquid; arises from cohesive forces at the surface.

Buoyancy

The upward force that allows objects to float; related to density and displacement.

Density of ice vs. water

Ice is less dense than liquid water, so ice floats; caused by the lattice structure of hydrogen bonds in ice.

Specific heat

The amount of heat required to raise the temperature of 1 gram of a substance by 1°C.

Calorie

The amount of heat required to raise the temperature of 1 gram of water by 1°C (1 cal ≈ 4.184 joules).

Heat capacity

The total amount of heat needed to raise the temperature of an object, not per gram.

Evaporation

The process by which a liquid becomes a gas, typically at the surface.

Evaporative cooling

Cooling that occurs as a liquid evaporates, removing heat from the surface or organism.

Heat of vaporization

The amount of heat required to convert 1 gram of liquid into vapor.

Solvent

The substance in a solution that dissolves the solute; water is a common solvent.

Solute

The substance dissolved in the solvent.

Dissociation (dissolution)

Process by which a solute separates into ions or molecules when dissolved (e.g., NaCl into Na+ and Cl− in water).

Solution

A homogeneous mixture of solute dissolved in solvent.

Ion

A charged particle formed when an atom gains or loses electrons.

Acid

A substance that increases hydrogen ion concentration in solution (lowers pH).

Base

A substance that decreases hydrogen ion concentration (raises pH) or provides hydroxide ions (OH−).

pH

A 0–14 scale measuring hydrogen ion concentration; below 7 is acidic, above 7 is basic, 7 is neutral.

Hydrogen ion (H+)

A positively charged ion indicating acidity; higher H+ means more acidic solutions.

Hydroxide ion (OH−)

A negatively charged ion associated with basic solutions.