Chemical Reaction

s

the process by which one or more substances are changed into one or

more different substances

Chemical Reaction

REACTANTSthe starting substances in

a chemical reaction(the stuff on the left)

PRODUCTSthe final substances in a

chemical reaction(the stuff on the right)

REPRESENTATION OF PHYSICAL STATES IN

EQUATIONS

• (g) = gas

• (l) = liquid

• (cr) = solid (stands for crystalline)

• (aq) = substance dissolved in water

WRITING BALANCED EQUATIONS

• STEP 1: Determine the reactants and the products

• STEP 2: Assemble the equation• STEP 3: Balance the equation (get

the same # of atoms of each element on each side)

WARNING!!!Never

Ever

EverCHANGE THE SUBSCRIPT

two or more substances combine

to form one new substance

SYNTHESIS

A + B ABSYNTHESIS

Na + Cl2 NaClPb(IV) + O2 Pb2O4

when a substance breaks up into

simpler substances

DECOMPOSITION

AB A + BDecomposition

NaCl Na + Cl2

Pb + O2Pb2O4

one element displaces another

in a compound

SINGLE DISPLACEMENT

Single Displacement Reaction

AB + C AC + B or CB + A

Single Displacement

NaBr + Cl2 NaCl + Br2

(NH4)2S + O2 (NH4)2O + S

DOUBLE DISPLACEMENT

the positive or negative portions of two compounds are

switched

AB + CD AD + CB

Double Displacement

NaBr + Pb2S3 Na2S + PbBr3

K2SO4 + Ba(OH)2 KOH + BaSO4

hydrocarbon reacts with oxygen to form carbon dioxide and

water

COMBUSTION (aka OXIDATION)

Writing Balanced Equations When Given Words Only

• STEP 1: Write out the symbols

• STEP 2: Balance your charges (if needed)

• STEP 3: Check for diatomics

• STEP 4: Balance Equation