6.1 Types of Chemical Reactions

6 Types of Reactions Synthesis (Combination) (3) Decomposition (3) Single replacement (4) Double Replacement (4) Neutralization (acid-base) (4) Combustion (4)

Synthesis Reactions 2 or more reactants combine to form a single product Element + Element  Compound A + B  AB Ex) 2Na + Cl 2  2NaCl + 

Synthesis Reactions -Do not write down- Make sure to consider the ion charge of both reactants before forming the product Mg 2+ O 2- both have 2- ion charge so they combine as Mg O Now balance Ex) 2Mg + O 2  2MgO

Practice Pg 259 #1/2 a,c,e Check answers- Pg 592

Decomposition Reactions Breaking down a compound into smaller compounds or elements Reverse of synthesis Compound  Element + Element AB  A + B 2NaCl  2Na + Cl 2 + 

Decomposition Reactions Both parts of the compound go back to their element form (no ion charge) If they are diatomic, make sure to write the 2

Practice Pg 260 #1/2 a,c, Check answers- Pg 592

Single Replacement Reactions An element and a compound react to produce another element and compound Element + Compound  Element + Compound A + BC  B + AC Metals and non-metals go together Example: 2Al + 3CuCl 2  3Cu +2AlCl 3 ++ 

Practice Pg 261 #1/2 a,c, Check answers- Pg 592

Double Replacement Reactions Two ionic solutions react to form two other ionic solutions Ionic solution + Ionic solution  Ionic solution + Ionic solid AB (aq) + CD (aq)  AD (aq) + CB (s) Ex) Pb(NO 3 ) 2 + 2NaI  PbI 2 + 2NaNO 3

Practice Pg 262 #1/2 a,c, Check answers- Pg 592

Neutralization Reaction Been done… check your notes! + + 

Combustion Reaction Organic compounds react with oxygen to produce carbon dioxide and water Ex) CH 4 + 2O 2  CO 2 + 2H 2 0 Ex) C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 

Practice Pg 264 #1/2 a,c Check answers- Pg 592 Now try the summary problems Pg 265 #1-7 Solutions on how to do them are on the following page

Reaction Rates How fast a reaction occurs Can be fast or slow

Temperature Increase temp = increase rxn rate Decrease temp = decrease rxn rate Warmer = molecules move faster = more collisions

Concentration Increased conc = increased rxn rate Decreased conc = decreased rxn rate More molecules = faster rxn

Surface Area Increase SA = increase rxn rate Decrease SA = decrease rxn rate What burns faster: kindling or a large log?

Catalyst Speeds up a rxn but is not used up Lower energy needed for rxn to start Eg: enzymes in your body Eg: catalytic converter in cars