1. Types of Chemical Reactions

2. Synthesis (Composition) Reactions
Two or more substances combine to form a
new compound.
A + X  AX
Reaction of elements with oxygen and sulfur
Reactions of metals with Halogens
Synthesis Reactions with Oxides
There are others not covered here!

3. Hydrogen reacting with oxygen
Reactions of elements with oxygen
Hydrogen reacting with oxygen
2H2(g) + O2(g)  2H2O(g)

4. Reaction of aluminum and bromine
…a metal with a halogen:
Reaction of aluminum and bromine
2Al(s) + 3Br2(g)  2AlBr3(s)

5. Decomposition Reactions
A single compound undergoes a reaction that
produces two or more simpler substances
AX  A + X
Decomposition of:
Binary compounds 2H2O(l )  2H2(g) + O2(g)
Metal carbonates CaCO3(s)  CaO(s) + CO2(g)
Metal hydroxides Ca(OH)2(s)  CaO(s) + H2O(g)
Metal chlorates 2KClO3(s)  2KCl(s) + 3O2(g)
Oxyacids H2CO3(aq)  CO2(g) + H2O(l )

6. Decomposition of Nitrogen Triiodide
2 NI3(s)  N2(g) + 3 I2(g)

7. Decomposition of Mercury(II) Oxide
Metal oxides decompose with heating…
Decomposition of Mercury(II) Oxide
2HgO(s)  2Hg(l ) + O2(g)

8. Catalyzed Decomposition of Hydrogen Peroxide
Some decomposition needs catalysis…
Catalyzed Decomposition of Hydrogen Peroxide
2H2O2(l )  2H2O(l ) + O2(g)

9. Single Replacement Reactions RedOx Reactons
A + BX  AX + B
BX + Y  BY + X
Replacement of:
Metals by another metal
Hydrogen in water by a metal
Hydrogen in an acid by a metal
Halogens by more active halogens

10. Redox (short for reduction–oxidation reaction) is a chemical reaction in which the oxidation states of atoms are changed. 
Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom, or ion.
Reduction is the gain of electrons or a decrease in oxidation state by a molecule, atom, or ion.

11. Reaction of copper with aqueous silver nitrate
A metal replaces another metal (in solution)…
Reaction of copper with aqueous silver nitrate
Cu(s) + 2AgNO3(aq)  Cu(NO3)2(aq) + 2Ag(s)

12. A metal replaces another metal (no solution needed!)…
The Thermite reaction
2Al(s) + Fe2O3(s)  Al2O3(s) + 2Fe(s)

13. Reaction of potassium with water
An active metal replaces hydrogen in water…
Reaction of potassium with water
2K(s) + 2H2O(l )  2KOH(aq) + H2(g)

14. Magnesium in Hydrochloric Acid
A metal replaces hydrogen in an acid…
Magnesium in Hydrochloric Acid
Mg(s) + 2HCl(aq)  MgCl2(aq) + H2(g)

15. Double Replacement Reactions
The ions of two compounds exchange places in an
aqueous solution to form two new compounds.
AX + BY  AY + BX
One of the compounds formed is usually a
precipitate, an insoluble gas that bubbles out of
solution, or a molecular compound, usually water.

16. Lead(II) nitrate reacts with potassium iodide
Double replacement forming a precipitate…
Lead(II) nitrate reacts with potassium iodide
Pb(NO3)2(aq) + 2KI(aq)  PbI2(s) + 2KNO3(aq)

17. Reaction of Hydrochloric acid and Sodium hydroxide
Double replacement forming water…
Reaction of Hydrochloric acid and Sodium hydroxide
HCl(aq) + NaOH(aq)  NaCl(aq) + H2O(l )

18. Combustion Reactions
A substance combines with oxygen, releasing a large
amount of energy in the form of light and heat.
Reactive elements combine with oxygen
P4(s) + 5O2(g)  P4O10(s)
(This is also a synthesis reaction)
The burning of natural gas, wood, gasoline
C3H8(g) + 5O2(g)  3CO2(g) + 4H2O(g)
______ + O2  CO2 + H2O

19. Reaction of white phosphorus and oxygen
An element burning in oxygen…
Reaction of white phosphorus and oxygen
P4(s) + 5O2(g)  P4O10(s)

20. More Reactions With Oxygen
2 Mg(s) + O2(g)  MgO(s)
4 Fe(s) + 3 O2(g)  2 Fe2O3(s)
P4(s) + 5 O2(g)  P4O10(s)
S8(s) + 8 O2(g)  8 SO2(s)

21. Hydrogen and oxygen reacting
Energy for space travel…
Hydrogen and oxygen reacting
2H2(g) + O2(g)  2H2O(g) + energy

22. Burning of natural gas…
Combustion of Propane
C3H8(g) + 5O2(g)  3CO2(g) + 4H2O(g)

23. Combustion of methanol
Burning of an alcohol…
Combustion of methanol
CH3OH(l ) + 2O2(g)  CO2(g) + 2H2O(g)

24. The Activity Series of the Metals
Lithium
Potassium
Calcium
Sodium
Magnesium
Aluminum
Zinc
Chromium
Iron
Nickel
Lead
Hydrogen
Bismuth
Copper
Mercury
Silver
Platinum
Gold
Metals can replace other metals
provided that they are above the
metal that they are trying to
replace.
Metals above hydrogen can
replace hydrogen in acids.
Metals from sodium upward can
replace hydrogen in water

25. The Activity Series of the Halogens
Fluorine
Chlorine
Bromine
Iodine
Halogens can replace other
halogens in compounds, provided
that they are above the halogen
that they are trying to replace.
2NaCl(s) + F2(g) 
2NaF(s) + Cl2(g)
???
MgCl2(s) + Br2(g) 
No Reaction
???