IIIIIIIVV Ch. 8 – Chemical Reactions III. Types of Chemical Reactions (p )

A. Combustion CH 4 (g) + 2O 2 (g)  CO 2 (g) + 2H 2 O(g) n the burning of any substance in O 2 to produce heat A + O 2  B

Na(s)+ O 2 (g)  C 3 H 8 (g)+ O 2 (g)  A. Combustion n Products:  contain oxygen  hydrocarbons form CO 2 + H 2 O CO 2 (g)+ H 2 O(g) Na 2 O(s) 4 2

B. Synthesis n the combination of 2 or more substances to form a compound n only one product A + B  AB

B. Synthesis H 2 (g) + Cl 2 (g)  2 HCl(g)

Al(s)+ Cl 2 (g)  AlCl 3 (s) B. Synthesis n Products:  ionic - cancel charges  covalent - hard to tell

C. Decomposition n a compound breaks down into 2 or more simpler substances n only one reactant AB  A + B

C. Decomposition 2 H 2 O(l)  2 H 2 (g) + O 2 (g)

KBr(l)  K(s) + Br 2 (l) 2 2 C. Decomposition n Products:  binary - break into elements  others - hard to tell

D. Single Displacement n one element displaces another in a compound  metal displaces metal (+)  nonmetal displaces nonmetal (-) A + BC  B + AC

D. Single Displacement Cu(s) + 2AgNO 3 (aq)  Cu(NO 3 ) 2 (aq) + 2Ag(s)

Fe(s)+ CuSO 4 (aq)  Cu(s)+ FeSO 4 (aq) D. Single Displacement n Products:  metal  metal (+)  nonmetal  nonmetal (-)  free element must be more active (check activity series) Br 2 (l)+ NaCl(aq)  N.R.

AB + CD  AD + CB E. Double Displacement n ions in two compounds “change partners” n cation of one compound combines with anion of the other

E. Double Displacement Pb(NO 3 ) 2 (aq) + K 2 CrO 4 (aq)  PbCrO 4 (s) + 2KNO 3 (aq)

Pb(NO 3 ) 2 (aq)+ KI(aq)  PbI 2 (s)+ KNO 3 (aq) E. Double Displacement n Products:  switch negative ions  one product must be insoluble (check solubility table) NaNO 3 (aq)+ KI(aq)  N.R. 2 2

Practice Problems: n 1. Li(s) + N 2 (g)  Synthesis 6Li(s) + N 2 (g)  2Li 3 N (aq) n 2. Mg(s) + CrCl 3 (aq)  Single Displacement 3Mg(s) + 2CrCl 3 (aq)  3MgCl 2 (aq) + 2Cr(s) NO REACTION!!

Practice Problems: n 3. CoBr 2 (s) Decomposition CoBr 2 (s)  Co(s) + Br 2 (l) n 4. C 4 H 8 (g) + O 2 (g)  Combustion C 4 H 8 (g) + 6O 2 (g)  4CO 2 (g) + 4H 2 O(g)

Practice Problems: n 5. KBr(aq) + AgNO 3 (aq)  Double Displacement KBr(aq) + AgNO 3 (aq)  KNO 3 (aq) + AgBr(s) n 6. NiI 2 (aq) + FeSO 4 (aq)  Double Displacement NiI 2 (aq) + FeSO 4 (aq)  NiSO 4 (aq) + FeI 2 (aq) NO REACTION!!

Time for a WS, then a lab! n Predicting Products WS n Predicting Products Lab