activity series  
  bond energy
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  common names

  conversion factors: energy

  conversion factors: length

  conversion factors: mass

  conversion factors: pressure

  conversion factors: temp.

  conversion factors: volume

  covalent prefixes

  density solver

  diatomic elements

  e-config. chart

  element list

  gas law formulas

  Ka's of polyprotic acids

  Ka's of weak acids

  Kb's of weak bases

  metric conversion chart

  mole conversion chart

  molecular geometries

  organic prefixes

  periodic table

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  pH/pOH converter

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  pressure converter

  SI units

  solubility chart

  solubility of salts rules

  solubility product constants

  stoichiometry chart

  temp. conversion

  temp. formulas

  thermodynamic data

  vapor pressure of water

Decomposition Reactions

A decomposition reaction is the opposite of a synthesis reaction. In a decomposition reaction a reactant compound is broken into two or more less complex substances. you are given a compound as the reactant. In most cases, to find the product you split the compound into the individual elements. The other types of decomposition reactions (decomposition of a hydrate, chlorate, carbonate, etc.) are covered in other tutorials. This tutorial focuses on the decomposition of a binary compound. The general pattern of a decomposition reaction is:
        AB --> A + B
Look at the example below.
Example #1:
2O(l) --> 2H2(g) + O2(g)
Water decomposes (usually with the help of electricity) to form hydrogen gas and oxygen gas. Hydrogen and oxygen are written with subscripts of 2 because they are both diatomic molecules.
Now let’s go step by step.
Predict the products when solid iron(II) oxide decomposes.
Description of Action
1. Write the formula for the given reactant. FeO(s) -->
2. On the products side of the equation, write the symbols for the two elements in the compound. Be sure to separate the elements by a + sign. If either of the elements is diatomic, be sure to write a 2 as its subscript. FeO(s) --> Fe(s) + O2(g)
Oxygen is diatomic, so it is written with a subscript of 2.
3. Balance the equation. 2FeO(s) --> 2Fe(s) + O2(g)

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