MACS 302 Exam 1 Water/Seawater

hydrogen bond

electrostatic force of attraction between partial positive charge of hydrogen atom bonded to an electronegative atom or group

Polarity

distribution of electrons within an atom

Electronegativity

tendency of an atom to attract electrons

• More electronegative atoms pull electrons towards them

Surface Tension & Viscosity

ST: tendency of fluid surfaces to shrink into the minimum surface area possible, stay together cus of H-bonds

barrier for biological systems, gas exchange

VIS: magnitude of internal friction, from cohesive molecular forces

How oceans/organisms move

Melting Point/Boiling Point

melts/boils at higher temperatures than predicted cus h-bond require more energy to be broken

Temperature

Measure of the average kinetic energy of atoms or molecules

amount of thermal energy per volume

Measured in degrees

Heat

Measure of the total amount of kinetic energy (amount of thermal energy)

Measured in calories

Specific Heat Capacity

amount of heat that must be added to one unit of mass of the substance in order to cause an increase of one unit in temperature

high

Density of water

Cold water is denser than warm water…

… so why does ice float?

lattice shape forms

Universal Solvent

Excellent solvent because water is a polar molecule

Hydration

the process in which an ion is surrounded

by water molecules arranged in a specific manner

latent heats of fusion (freezing) and vaporization

energy released or absorbed, by a body, during a constant-temperature process (such as a phase change)

Ionic Bond

chemical bond that's formed when electrons are transferred from one atom to another

Covalent Bond

chemical link where two atoms share pairs of electrons, allowing each atom to achieve a stable, full outer electron shell

Solute vs Solvent

solute: minor component in a solution, dissolved in the solvent.

solvent: major component

Intermolecular Force

the attractive forces that exist between molecules, weaker than bonds

Dipole

separation of the positive and negative electric charges

Solid vs liquid vs gas

solid: state of matter in which atoms are closely packed and are difficult to move

volume: definite volume but no fixed shape

gas: state of matter with neither fixed volume nor fixed shape

Sensible vs Latent Heat

Sensible heat changes a substance's temperature and can be felt (like warming water), while latent heat changes its state (solid, liquid, gas) without changing temperature

Ion

atom or molecule with a net electrical charge

• cation = positive charge

• anion = negative charge

Salinity

the dissolved inorganic salt content of a body of water

Chlorinity

a measure of the concentration of chloride ions (and other halides like bromide, iodine) in water, especially seawater, expressed in grams per kilogram (g/kg) or parts per thousand (ppt).