Chemistry Final Study Guide

Qualitative observation

Physical observations of a substance

Quantitative observations

Numerical observations of a substance

Aqueous solution

A solution dissolved in liquid

Extensive properties

A property that depends on the amount of matter present (Volume, mass, weight)

Intensive properties

Properties that do not depend on the amount of matter (Density, temperature, boiling point)

Physical properties

Can be observed without changing the identity of the substance (mass, state, density)

Physical change

A change that doesn’t affect the substances identity

Chemical properties

Can only be observed by changing the composition of the substance

Chemical change

The change of a substance into a new substance

Independent variable

The manipulated variable (hypothesized cause)

Dependent variable

The observed variable (the effect)

Constant

Any factor that is kept the same

Experimental group

The group being changed and exposed to the independent variable

Control group

The group kept under normal conditions

Neutral atom

Has equal numbers of electrons and protons

Isotopes

An element that has the same amount of protons but different amount of neutrons, giving it a different mass

Mass number

Protons + neutrons

Nuclear force

Holds the nucleus together by overriding the repelling force between protons

Quarks

Particles that make up protons and have a strong attractive force

Electromagnetic force

Holds the electrons to the nucleus

Wavelength

The distance between two wave crests

Frequency

The number of wave cycles that passes a given point per second

Energy

The amount of chemical work the photon of the wave can perform

Excited electron

Happens when an electron absorbs energy and jumps from a stable ground state to a higher energy level

Valence electrons

The electrons in the outermost shell of an atom that form bonds

Cations

Has a positive charge due to a loss of electrons

Anions

Has a negative charge due to a gain of electrons

Metals

Increase in reactivity as you move down and left in the periodic table

Non metals

Increase in reactivity as you move up and right in a periodic table

Magnetic quantum number

Identifies the orientation of an orbital around a nucleus

Angular momentum quantum number

Identifies the shape of the orbital

Intramolecular forces

Strong chemical bonds inside a molecule, holding its specific atoms together

Intermolecular forces

Attractive forces that exist between seperate molecules that determine physical properties

Ionic bonds

Formed by the transfer of electrons from a metal to a non metal

Covalent bond

Formed by the sharing of electrons between two non metals

Symmetrical shapes

Non polar

Asymmetrical shapes

Polar

London dispersion

The weakest force formed through temporary attractive forces in all molecules

Dipole-Dipole

Moderately strong force formed between one polar molecule and one non-polar molecule

Hydrogen bond

Strongest force formed between a hydrogen to N, O, or F

VSEPR Theory

Electron pairs repel each other causing each electron domain to spread as far apart as possible, determines 3D shape

Precipitate

An insoluble solid formed during a chemical reaction from 2 aqueous solutions

Synthesis

A+B=AB

Decomposition

AB=A+B

Single Replacement

AB+C=AC+B

Double replacement

AB+CD=AD+BC

Combustion

Hydrocarbon+O2=CO2+H2O

Le Chateliers principal

Systems at equilibrium counter changes to stay stable and balanced

Solid

Definite shape and volume. Particles vibrate in place

Liquid

Indefinite shape. Definite volume. Particles slide past each other

Gas

Indefinite shape and volume. Particles move rapidly and freely

Boyles Law

Pressure and volume are inversely relates. P1V1=P2V2

Charles Law

Volume and temp are directly related. V1/T1=V2/T2

Gay-Lussacs Law

Pressure and temp are directly related. P1/T1=P2/T2

Combined Gas law

P1V1/T1=P2V2/T2

Ideal Gas Law

PV=nRT

Boiling

Liquid to gas throughout substance

Evaporation

Liquid to gas only at surface

Melting

Solid to liquid

Freezing

Liquid to solid

Sublimation

Solid to gas

Deposition

Gas to solid

Condensation

Gas to liquid

Fluidity

Ability of a substance to flow easily

Capillary action

Liquid rising slowly in a narrow tube driven by cohesion and adhesion

Pressure

Force exerted per unit of surface area

What happens if the temperature of an exothermic reaction is increased?

Reverse reaction

Add reactant

Forwad reaction

Add product

Reverse reaction

Remove reactant

Reverse reaction

Remove product

Forward reaction

What happens if the temperature of an endothermic reaction is increased?

Forward reaction

What happens if the temperature of an endothermic reaction is decreased?

Reverse reaction

What happens if the temperature of an exothermic reaction is decreased?

Reverse reaction

Exothermic

Releases heat - Product

Endothermic

Absorbs heat - Reactant

Evidence of a chemical reaction

Release of light or heat, heat absorbed, color change, odor change, gas release

Pressure increase

Reaction favors whichever produces less gas molecules

Linear

2 electron domains

Trigonal planar

3 electron domains

Tetrahedral

4 electron domains

Trigonal bipyramidal

5 electron domains

Octahedral

6 electron domains

Bent

4 electron domains; 2 bonding pairs, 2 lone pairs (sometimes 1)

Trigonal pyramidal

4 electron domains; 3 bonding pairs, 1 lone pair