Moles and Stochiometry

Types of Chemical Reactions

Five Types

  1. Synthesis: multiple reactants to make one product. A+B > AB

  2. Decomposition: one reactant makes multiple products. AB > A+B

  3. Single Replacement/Displacement: element and compound react to produce a different element and compound.

  4. Double Replacement/Displacement: two compounds exchange cations to produce two different compounds. AB+CD > AD+CB.

  5. Combustion: A carbon compound reacts with gas, producing carbon dioxide and water. CH4 + O2 > CO2 + H2O

Predicting Products

  • Binary compound: Product is the two elements in the compound

  • Reactant is a metal carbonate: Product is a metal oxide and carbon dioxide

  • Reactant is a metal chlorate: Product is a metal chloride and oxygen

  • Reactant is two elements: Product is a binary compound

  • Reactant is a metal oxide and water: Product is a metal hydroxide

  • Reactant is a nonmetal oxide and water: Product is an acid (H and polyatomic)

  • Reactant is an element and a compound: Product is an element and a compound (“likes” replaces “likes”). Single element must be above compound element in series).

  • Reactant is two compounds: Product is two compounds (switch the first ions)

  • Product is a carbon compound with oxygen: Products are carbon dioxide and water

Stoichiometry

  • Shows the mathematical relationships within a balanced equation.

  • Equation must be balanced to solve a stoichiometry problem.

Steps:

  1. Change given(s) to moles

  2. Convert to the new substance using coefficient ratios

  3. Change to unit wanted

Limiting Reactants/Reagants

  • Limit or restrict the amount of product produced.

  • Limiting reactant is consumed during the reaction.

  • Excess reactant remains after the limiting reactant used up.