6 2 Types of Reactions Types of Reactions

(6 -2) Types of Reactions

Types of Reactions: 1. Synthesis: A + B → C 2. Decomposition: A → B + C 3. Single-displacement: A + BC → AC + B 4. Double replacement: AB + CD → AD + CB 5. Combustion: Hydrocarbon + oxygen → carbon dioxide + water + energy

Synthesis When two substances combine to form a compound. – Rusting of iron: (producing iron (III) oxide) 4 Fe + 3 O 2 → 2 Fe 2 O 3 – Acid rain: (producing carbonic acid) H 2 O + CO 2 → H 2 CO 3 – Formation of iron sulfide: Fe + S → Fe. S

Decomposition A compound breaks into two or more simpler substances. Mercury (II) oxide → mercury + oxygen. 2 Hg. O → 2 Hg + O 2 Hydrogen peroxide → water + oxygen 2 H 2 O 2 → 2 H 2 O + O 2 Ammonium nitrate → dinitrogen monoxide + water NH 4 NO 3 → N 2 O + 2 H 2 O

Single-Displacement One element takes the place of another in a compound. Iron + copper (II) sulfate → Iron (II) sulfate + copper Fe + Cu. SO 4 → Fe. SO 4 + Cu chlorine + sodium bromide → sodium chloride + bromine Cl 2 + 2 Na. Br → 2 Na. Cl + Br 2

Double-Displacement The positive portions of two ionic compounds are exchanged Lead nitrate + potassium iodide → potassium nitrate + lead iodide Pb(NO 3)2 + 2 KI → 2 KNO 3 + Pb. I 2

Combustion When a substance combines with oxygen to form oxide(s) Acetylene + oxygen → carbon dioxide +water+ energy 2 C 2 H 2 + 5 O 2 → 4 CO 2 + 2 H 2 O + energy Propane + oxygen → carbon dioxide + water + energy C 3 H 8 + 5 O 2 → 3 CO 2 + 4 H 2 O + energy

Review Question

Answer • Decomposition • Synthesis • Double displacement • Single displacement