Gen Chem 1: Chapter 4: Chemical Reactions

3 techniques for balancing equations

1. balance elements last

2. balance polyatomic ions (rather than atoms)

3. use fractional coefficients for diatomic molecules

decomposition

AB —> A + B

Combination (Synthesis)

A + B —> AB

Single Displacement Reaction

AB + C —> AC + B

Double Displacement

AB + CD —> AD + BC

metal-nonmetal reaction

• type of reaction: synthesis

• starting materials: metal + nonmetal

• products: ionic cmpd

• redox

combustion

• type of reaction: synthesis

• starting materials:

  • element + oxygen

  • hydrocarbon + oxygen

• products:

  • oxide cmpd

  • CO₂ + H₂O

• redox

precipitation

• type of reaction: double displacement

• starting materials: 2 soluble cmpds

• products: insoluble cmpd (precipitate)

• NOT redox

acid-base neutralization

• type of reaction: double displacement

• starting materials: acid + base

• products: water + salt

• NOT redox

metal displacement

• type of reaction: single displacement

• starting materials: metal + cation

• products: cation + metals

• redox

metal-acid

• type of reaction: single displacement

• starting materials: metal + acid (H⁺)

• products: cation + H₂(g)

• redox

INC charge on ions —> ____ (tightly/loosely) sticks —> ___ (INC/DEC) solubility

INC charge on ions —> TIHTLY sticks tg —> DEC solubility

ex: Fe³⁺ + O^2- = Fe₂O₃ is insoluble bc lots of charge