Chemistry Unit #9 Terms

Front 1

Valence Shell Electron Pair Repulsion Theory (VSEPR)

Back 1

the geometric arrangement of atoms about a central atom in a covalent compound is determined solely by the repulsions between electron pairs present in the valence shell of the central atom

Front 2

Unique Properties of Water

Back 2

polar; forms hydrogen bonds; bent; high boiling point;

Front 3

Boiling Point

Back 3

the temperature at which bonds the molecules of a liquid begin to separate and enter the gas state

Front 4

Vapor Pressure

Back 4

relates to the tendency of particles to escape from the liquid

Front 5

Freezing Point

Back 5

characteristic temperature at which a liquid turn into a solid

Front 6

Surface Tension

Back 6

property of the surface of a liquid that allows it to resist an external force

Front 7

Capillary Action

Back 7

the ability of liquid to flow against gravity where liquid spontaneously rises in a narrow space such as a thin tube

Front 8

Adhesion

Back 8

any attraction process between dissimilar molecular species that can potentially bring them in "direct contact"

Front 9

Cohesion

Back 9

property of like molecules sticking together, being mutually attractive

Front 10

Density of Solid

Back 10

something's mass per unit volume

Front 11

Polar Covalent Bonds

Back 11

the electrons shared by the atoms spend a greater amount of time, on the average, closer to the Oxygen nucleus than the Hydrogen nucleus. This is because of the geometry of the molecule and the great electronegativity difference between the Hydrogen atom and the Oxygen atom

Front 12

Hydrogen Bond

Back 12

the attractive interaction of a hydrogen atom with an electronegative atom; The hydrogen must be covalently bonded to another electronegative atom to create the bond

Front 13

Electronegativity

Back 13

chemical property that describes the tendency of an atom or a functional group to attract electrons (or electron density) towards itself and thus the tendency to form negative ions.

Front 14

Moving Left --> Right

Back 14

- Atomic Radius Decreases
- Ionization Energy Increases
- Electronegativity Increases

Front 15

Moving Top --> Bottom

Back 15

- Atomic Radius Increases
- Ionization Energy Decreases
- Electronegativity Decreases

Front 16

Polar Molecule

Back 16

A polar molecule is a bit like a magnet: the two ends of magnet are different

Read more: http://wiki.answers.com/Q/What_is_a_polar_molecule#ixzz1IcGOjSjv

Front 17

Non-Polar Molecule

Back 17

Molecule which has no separation of charge, so no positive or negative poles are formed

Front 18

Dipole

Back 18

has two oppositely charged sides

Front 19

Intermolecular Forces

Back 19

(forces between two molecules) are weak compared to the intramolecular forces (forces keeping a molecule together)

Front 20

Solvation of Ionic Solids

Back 20

the process of attraction and association of molecules of a solvent with molecules or ions of a solute. As ions dissolve in a solvent they spread out and become surrounded by solvent molecules.

Front 21

Solution

Back 21

a homogeneous mixture composed of two or more substances

Front 22

Solute

Back 22

substance dissolved in solvent, forming a solution

Front 23

Solvent

Back 23

a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution

Front 24

Hydration Shell

Back 24

When a solute is being dissolved in an aqueous (water) solution the partially positive H atoms surround the solute (forming a shell) and attach to make bonds with the atoms of the solute, breaking them apart and making them part of the solution.

Front 25

Molarity

Back 25

mols per liter of solution

Front 26

Method for making solutions of a given molarity

Back 26

M1 x V1 = M2 x V2

Front 27

Dilution

Back 27

the process of reducing the concentration of a substance

Front 28

Colligative Properties

Back 28

properties of solutions that depend on the number of molecules in a given volume of solvent and not on the properties/identity (e.g. size or mass) of the molecules.

Front 29

London Dispersion Forces

Back 29

a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles. (happens with non-polar compounds)