Predicting Unit_Class Notes.docx

5 Pages
Unlock Document

CHEM 1061
Hyunjoo Im

Class Notes I. Decomposition Reaction  Tends to start w/ 1 reactant simpler substances  Tend to form common simple substances as products; ex: N , H O2 CO2, simp2e salts  Key words: something starts it: ―heated‖, ―catalyst‖, ―current‖  Ex: A sample of limestone containing calcium carbonate is heated oCaCO → C3 + CaO 2 o*AP: nothing above arrow = graded oRule: carbonates always decompose into CO and wh2t’s left over  Memorize (mem): Ammonia is electrically decomposed o2NH → N + 3H (above arrow = lightening bolt) 3 2 2  *AP: Balance the equation! Even if wrong reaction’s balanced, still get point (pt.) for balancing  Mem: Chlorates always form simple salt + O 2 oEx: Potassium Chlorate is strongly heated, 2KClO → 2KC3 + 3O 2  *AP: States of matter for the reaction not counted unless stated in the problem  Mem: Hydrogen Peroxide is decomposed o2H O 2 2H O + O2 2 II. Combustion Reactions  Each element in reactant combines w/ O 2  Key words: ―burned‖, ―reacted in O ‖,2air = O 2  Look for common substances oC + O → 2O 2 oN + O → 2O 2 oS + O →2SO (or S2 if pro3lem says ―excess O ) 2  Ex: Oxygen gas is mixed w/ ammonia in the presence of platinum (common catalyst) o4NH + 7O → 4NO + 6H O 3 2 2 2 oCombine every element w/ O  Ex: Solid zinc sulfide is heated in excess oxygen oZnS + 2O → Z2O + SO 3  Combustion of hydrocarbon oC H3+ 8O → 4H2O + 3CO2 2 III. Synthesis Reactions (Combination)  2 reactants  1 product  Look for possibility to form simple polyatomic salts/common compounds look for polyatomic ions  Key words: ―gas is passed (over)‖  Ex: Sulfur dioxide gas is passed over solid calcium oxide oSO 2(g) CaO →(s)SO 3 oIf sulfur trioxide passed  SO 3(g)+ CaO →(s)SO 4  Ex: A piece of lithium metal is dropped into a container of nitrogen gas o6Li + N →22i N 3  Halogen substitutions: alkene is exposed to a halogen, halogen replaces double bond oEx: propene gas is mixed with bromine vapor  C 3 +6Br → 2 H Br3 6 2 —C—C = C + Br → —C2C—C— Br Br IV. Precipitate/Net Ionic Reaction  Must have at least one solid, liquid, or gas formation  *AP: there’s never ―no reaction‖, everything works  Must get rid of spectator ions in final reaction  How to: o1) Predict Products (swap cations) o2) Check solubility; product always = solid unless water (l), diatomic (g), or otherwise stated o3) Erase spectator ions o4) Balance & rewrite equation  Solubility Rules oAlways Soluble: Nitrates, Acetates, Perchlorates, Group 1 metals, ammonium salts 2+ + 2+ oSoluble except: {chlorides, bromides, iodides} except w/ Pb , Ag , Hg , 2+ 2+ 2+ 2+ {sulfates} except Pb , Sr , Hg 2 , Ba oInsoluble Except: {Carbonates, phosphates} except w/ an always solu
More Less

Related notes for CHEM 1061

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.