Chapters 7 and 8

(s)

(s)

solid

(l)

liquid

(g)

gas

-->

yields

△

heat

-->

<--

reversible reaction

(↑)

gas given off

(↓)

precipitate formed

Synthesis reaction

A + B --> AB

Decomposition reaction

AB --> A + B

Single Replacement

AB + C --> AC + B

Double Replacement

AB + CD = AD + CB

Combustion Reaction

a chemical reaction that occurs when a substance reacts with oxygen, releasing energy in the form of heat and light (CO2 and H2O)

Signs a chemical reaction has occurred

formation of a solid, color change, bubbles formed, heat/light produced, flame occurs, temperature change

exothermic reactions

reactions that release energy and heat (make something warmer)

endothermic reactions

reactions that absorb energy and heat (make something cooler)

Law of Conservation of Mass

matter cannot be created or destroyed in a chemical reaction

Dissociation vs. decomposition

dissociation: molecule--atom; decomposition: substance--other substance(s)

Nitrate

NO3-

Sulfate

SO4 2-

Phosphate

PO4 3-

Carbonate

CO3 2-

hydroxide

OH-

acetate

C2H3O2-

bicarbonate

HCO3-

ammonium

NH4+

chlorate

ClO3-

chromate

CrO4 2-

Gas that puts out a burning wood splint

CO2

if a reaction causes something to "neutralize" you will always end up with:

a salt and water

A gas that pops when lit by fire

H2

Limewater

Ca(OH)2

Limestone

CaCO3

Quicklime

CaO

Gas that causes something to burn faster

O2

Chemical changes

Rearrangement of how atoms are grouped

Driving forces that pull reactants towards products

formation of a solid, of water, or of a gas, or transfer of electrons

Strong electrolyte

a substance that dissolves in water by dissociating completely into ions

Acetic acid

HC2H3O2

Sulfuric acid

H2SO4