Water and Life

These flashcards cover essential vocabulary and concepts related to the properties of water and its significance in biological systems.

Polar covalent bonds

Bonds in water molecules that result in hydrogen bonding.

Hydrogen bonding

Weak attractions between oppositely charged regions of water molecules.

Cohesion

The linking together of like molecules, often by hydrogen bonding.

Adhesion

The clinging of one substance to another.

Surface tension

A measure of how difficult it is to stretch or break the surface of a liquid.

Moderation of temperature

Water's ability to stabilize temperature by absorbing/releases heat.

Kinetic energy

Energy of motion, related to the speed of molecules.

Thermal energy

Total kinetic energy associated with random movement of atoms or molecules.

Temperature

Average kinetic energy of molecules in a body of matter.

Heat

Thermal energy in transfer from one body to another.

Calorie

The amount of heat required to raise the temperature of 1 gram of water by 1 degree Celsius.

Specific heat

The amount of heat must be absorbed or lost for 1 g of a substance to change its temperature by 1 degree Celsius.

Evaporation

The process of converting liquid into vapor.

Heat of vaporization

The quantity of heat a liquid must absorb for 1 g of it to convert to gas.

Evaporative cooling

The process in which the surface of an object becomes cool during evaporation.

Floating of ice

Ice floats because it's less dense as a solid than as a liquid.

Hydrophilic

Having an affinity for water.

Hydrophobic

Having no affinity for water; tends to form droplets.

Solution

A liquid that is a completely homogeneous mixture of two or more substances.

Solvent

The dissolving agent of a solution.

Solute

The substance that is dissolved in a solution.

Aqueous solution

A solution in which water is the solvent.

Molecular mass

The sum of the masses of all the atoms in a molecule.

Molarity

The number of moles of solute per liter of solution.

Acidic solution

A solution with higher concentrations of H+ than OH-.

Basic solution

A solution with higher concentrations of OH- than H+.

Hydrogen ion (H+)

A single proton with a 1+ charge.

Hydroxide ion (OH-)

A water molecule that has lost a proton.

Hydronium ion (H3O+)

A water molecule that has gained an extra proton.

pH scale

A measure of the acidity or basicity of a solution.

Buffer

A substance that minimizes changes in pH levels in a solution.

Ocean acidification

The lowering of ocean pH due to excess CO2 dissolving in seawater.

Emergent properties of water

Unique properties that arise from hydrogen bonding, aiding life.

Cohesive behavior

Water's ability to stay close together due to hydrogen bonding.

Temperature moderation

Water's capacity to absorb and release heat with minimal temperature change.

Expansion upon freezing

Water expands as it solidifies, making ice less dense.

Versatility as a solvent

Water's ability to dissolve a variety of substances.

Caloric requirements

Heat needed to change the temperature of water.

Hydration shells

Layers of water molecules that surround solute particles.

Biological fluids

Fluids in organisms that are buffered to maintain pH.

Carbonic acid

Weak acid formed when CO2 dissolves in water.

Acidic solutions

Solutions that increase H+ concentrations.

Basic solutions

Solutions that decrease H+ concentrations.

Concentration

Amount of solute in a given volume of solution.

Temperature stability

Water's ability to resist temperature change.

Heat absorption

Process of retaining heat in water through hydrogen bonds.

Thermal equilibrium

The state where two objects reach the same temperature.

Electronegativity

Tendency of an atom to attract electrons.

Water's structure

Arrangement of H2O molecules leads to unique properties.

Atomic mass unit (amu)

A unit used to measure atomic and molecular mass.

Moles

A unit measuring quantity of substance in grams equivalent to the molecular mass.

Avogadro's number

The number of particles in one mole, approximately 6.02 x 10²³.

Water vapor

Moisture in the air that can affect temperature regulation.

Sulfuric acid

An example of a strong acid that dissociates completely in water.