Key Vocab & Topics | AP Chemistry: Unit 4

Physical Change

Inter-Molecular Forces are being broken & formed between pure substances, solutes, and solvents.

Phase Change

Mixing with no new substances forming

Change in particle size, texture, or shape with no change in composition

Separation of mixture by physical means

Chemical Change

Chemical bonds are broken & formed resulting in new chemical substances with different chemical compositions

Change in energy involving light or heat

Precipitate formed from aqueous solutions

Gas formed not due to phase change

Odor produced that is associated with new substance

Color change that isn’t physical

Mobile Ions

Ions that are able to conduct electricity due to being able to move around

Does conduct electricity

Free moving state of matter (liquid or gas) & contains ions (charged particles for electricity to travel through)

Does not conduct electrivity

Fixed position (solid) or covalent bond (no charged ions)

Ionic Bond/Solute

Is able to be disassociated in water (split apart/dissolve)

Covalent Bond/Solute

Cannot disassociate in water (split apart/dissolve)

Soluble

SNAP (Sodium, Nitrate, Ammonium, Potassium) or Group 1A Metals

Insoluble

Anything without SNAP or Group 1A Metals

LEO GER

Lose electrons: Oxidation

Gain electrons: Reduction

Oxidation Number Rules (In order of priority)

Elemental Form/By Itself: 0

REMEMBER POLYATOMIC ION CHARGES

Group 1 Metals: +1

Group 2 Metals: +2

Fluorine: -1

Hydrogen: +1 when nonmetals, -1 when metals

Oxygen: -2, few exceptions

Cl, Br, I: -1 in Binary Compounds

Acid

Substance before it loses an electron, turns into Conjugate Base

Base

Substance before it gains an electron, turns into Conjugate Acid

Conjugate Acid

Substance after it gains an electron, comes from Base

Conjugate Base

Substance after it loses an electron, comes from Acid

pH Equivalence Point

Chemical Reaction is balanced; has reached preferred pH

Strong Acid + Strong Base = 7

Strong Acid + Weak base = <7

Weak Acid + Strong Base = >7

To Find Moles in Titration…

Then convert to the other element

Multiply the M and L…

Then balance the moles with the element you want to convert to

Strong Acids

Strong acids contain H at beginning:

HCl

HBr

HI

HClO3

HCLO4

HNO3

H2SO4

Everything else is Weak Acid

Strong Bases

Strong bases contain Group 1 & 2 Metal Hydroxides

LiOH, Na OH, KOH

Ca(OH)2, Sr(OH)2, BA(OH)2

Everything else is Weak Base