Chapter 6: Chemical Reactions

 Classify chemical reactions.

 A synthesis reaction is a reaction in which two or more substances react to produce a single product.  When two elements react, the reaction is always a synthesis reaction.

 Two compounds can also react to create one compound in a synthesis reaction.

 All synthesis reactions follow this general equation:  A + B  AB

 A decomposition reaction is one in which a single compound breaks down into two or more elements or new compounds.

 Decomposition reactions often require an energy source, such as heat, light, or electricity, to occur.  Decomposition reactions follow this general equation:  AB  A + B

 In a single-displacement reaction, one element displaces another in a compound.

 Usually a metal will replace another metal, or a halogen will replace another halogen in single displacement reactions  Single displacement reactions follow this general equation:  A + BC  AC + B

 Double displacement reactions occur when ions exchange between two compounds.

 Double displacement reactions will always produce either a precipitate, water, or a gas.  A double-displacement reaction follows the general form  AB + CD  AD + BC

 Classify the following reactions:  Na 2 O(s) + H 2 O(l) 2 NaOH(aq)  Ba(NO 3 ) 2 (aq) + K 2 SO 4 (aq) BaSO 4 (s) + 2 KNO 3 (aq)

 2 Al(s) + Fe 2 O 3 (s) Al 2 O 3 (s) + 2 Fe(l)  2 H 2 O 2 (aq) 2 H 2 O(l) + O 2 (g)  Solid calcium reacts with chlorine gas to produce solid calcium chloride.

 Write a balanced chemical equation for each synthesis reaction:  Ag(s) + Br 2 (g)   Mg(s) + Cl 2 (g) 

 Write a balanced chemical equation for each decomposition reaction:  Al 2 O 3 (s)   H 2 O(l) 