Classifying Chemical Reactions Unit 5.3

Classifying Reactions Four main types of chemical reactions 1.synthesis 2.decomposition 3.single replacement 4.double replacement

1. Synthesis Reaction Video: Video: Synthesis- two substances combine to form a single substance. – A + B  AB – Visual: – 2 simpler substances  one compound Ex: Fe + S  FeS

2. Decomposition Reaction Video: Video: Decomposition - One compound breaks down into 2 simpler substances. – opposite of synthesis – AB  A + B – Visual: – Compound  2 simpler substances Ex. 2H 2 O → 2H 2 + O 2 Ex: 2Hg(SCN) 2 → 2HgS + CS 2 + C 3 N 4

3. Single Replacement Reaction Video: Video: Single replacement - one element replaces another element in a compound – A + BC  AC + B – Visual: – Element + compound  new compound + new element Ex: Zn + CuSO 4  ZnSO 4 + Cu

4. Double Replacement Reaction Video: Video: Double replacement- the cation of one compound replaces the cation of the other – AB + CD  CB + AD – Visual: – 2 compounds  2 new compounds Ex: Pb(NO 3 ) 2 + K 2 CrO 4 → PbCrO 4 + KNO 3

Combustion Reactions Video: Video: This is not one of the 4 main types Combustion: a reaction that involves a hydrocarbon and oxygen that produces carbon dioxide and water – Hydrocarbon: a compound that contains ONLY Hydrogen and Carbon – Ex. CH 4 + 2O 2 → CO 2 + 2H 2 O