1. IIIIIIIVV Chemical Reactions Types of Chemical Reactions

2. When writing Chemical Rxns… n It is important to indicate what “state” the atom/molecule is in  (s): solid  (l): liquid  (g): gas  (aq): aqueous solution – a solution in which the solvent is water n ∆: heat

3. A. Combustion The burning of any substance in O 2 to produce heat A + O 2  CO 2 + H 2 O

4. C 3 H 8 (g)+ O 2 (g)  5 3 4 A. Combustion n Reactants: Hydrocarbon and Oxygen (O 2 ) n Products: Carbon Dioxide (CO 2) + Water (H 2 O) CO 2 (g)+ H 2 O(g) Most difficult to balance. Save oxygen for LAST!

5. Practice with combustion rxns. n Write a balanced equation for the complete combustion of the following:  Butene (g); C 4 H 8 - C 4 H 8 + 6O 2 → 4CO 2 + 4H 2 O  Glucose (s); C 6 H 12 O 6 - C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O  Octane (l); C 8 H 18 - 2C 8 H 18 + 25O 2 → 16CO 2 + 18H 2 O

6. B. Synthesis/Combination The combination of 2 or more substances react to form a single compound A + B  AB

7. Al(s)+ Cl 2 (g)  AlCl 3 (s) 2 3 2 B. Synthesis/Combination Products:  Only ONE product  ionic - cancel charges  covalent - hard to tell Watch for DIATOMIC molecules!

8. Practice with Synthesis Rxns. n Write balanced chemical equations for the following:  Mg + O 2.  - 2Mg + O 2 → 2MgO  P + O 2 → Diphosphorous pentoxide - 4P + 5O 2 → 2P 2 O 5  Ca + S  - Ca + S → CaS  Fe + O 2 → Iron (II) oxide - 2 Fe + O 2 → 2FeO

9. C. Decomposition A compound breaks down into 2 or more simpler substances AB  A + B

10. KBr(l)  K(s) + Br 2 (l) 2 2 C. Decomposition Products:  binary - break into elements  others - hard to tell Watch for DIATOMIC molecules!

11. Practice with Decomposition Rxns. n Write balanced chemical equations for the following:  HBr  - 2HBr → H 2 + Br 2  NaCl  - 2NaCl → 2Na + Cl 2  Ag 2 O  - 2Ag 2 O → 4Ag + O 2  Mercury (II) oxide  - 2HgO → 2Hg + O 2

12. D. Single Replacement One element replaces another in a compound A + BC  B + AC

13. D. Single Replacement Products:  metal replaces metal (+)  nonmetal replaces nonmetal (-)  free element must be more active (check activity series)

14. Fe(s)+ CuSO 4 (aq)  Cu(s)+ FeSO 4 (aq) D. Single Replacement Br 2 (l)+ NaCl(aq)  N.R. Watch for DIATOMIC molecules!

15. Practice w/Single Replacement Rxns. n Write balanced chemical equations for the following:  Mg(s) + Zn(NO 3 ) 2 (aq) - Mg(s) + Zn(NO 3 ) 2 (aq) → Mg (NO 3 ) 2 (aq)+ Zn(s)  Mg(s) + LiNO 3 (aq) - Mg(s) + LiNO 3 (aq) → No rxn.  Al + H 2 SO 4 - 2Al +3H 2 SO 4 → Al 2 (SO 4 ) 3 + 3H 2  Li + H 2 O - 2Li + 2H 2 O → 2LiOH + H 2

16. S.R with water n Change the formula of water from H 2 O to HOH (think of it as hydrogen hydroxide). n If it can be replaced it will always form a metal and hydroxide n Na + H 2 O n Na + HOH n Na is more active the H n Forms H 2 + NaOH (+1 & -1 charges cancel)

17. AB + CD  AD + CB E. Double Replacement Ions in two compounds “change partners”. The cation of one compound combines with anion of the other

18. Pb(NO 3 ) 2 (aq)+ KI(aq)  PbI 2 (s)+ KNO 3 (aq) E. Double Replacement Products:  switch negative ions  one product must be insoluble (check solubility table in CRM)  Need to worry about charges NaNO 3 (aq)+ KI(aq)  N.R. 2 2 Must include state of matter!

19. Practice with Double Displacement Rxns. n Write balanced chemical equations for the following:  HCl + Ca(OH) 2 - 2HCl + Ca(OH) 2 → N.R.  KOH + H 3 PO 4 - 3KOH + H 3 PO 4 → K 3 PO 4 + 3H 2 O  Al(OH) 3 + H 2 SO 4 - 2Al(OH) 3 + 3H 2 SO 4 → N.R.  SrBr 2 + (NH 4 ) 2 CO 3 - SrBr 2 + (NH 4 ) 2 CO 3 → 2NH 4 Br + SrCO 3