Simple Chemical Reaction Guide
Synthesis (Combination) Reaction
A synthesis reaction occurs when two or more simple substances (reactants) combine to form a single, more complex substance (product).
General Formula:
Visual Guide:
Example: Formation of Water
Hydrogen gas ($H_2$) combines with oxygen gas ($O_2$) to form liquid water ($H_2O$).
Decomposition Reaction
A decomposition reaction is the opposite of synthesis. A single complex compound breaks down into two or more simpler substances.
General Formula:
Visual Guide:
Example: Decomposition of Hydrogen Peroxide
Hydrogen peroxide ($H_2O_2$) decomposes into water ($H_2O$) and oxygen gas ($O_2$).
Single Displacement Reaction
A single displacement (or replacement) reaction occurs when a more reactive element displaces a less reactive element from a compound.
General Formula:
Visual Guide:
Example: Zinc and Hydrochloric Acid
Solid zinc ($Zn$) reacts with hydrochloric acid ($HCl$) to produce zinc chloride ($ZnCl_2$) and hydrogen gas ($H_2$).
Double Displacement Reaction
A double displacement (or metathesis) reaction occurs when the positive ions (cations) and negative ions (anions) of two ionic compounds exchange places.
General Formula:
Visual Guide:
Example: Silver Nitrate and Sodium Chloride
Silver nitrate ($AgNO_3$) reacts with sodium chloride ($NaCl$) to form solid silver chloride ($AgCl$) and sodium nitrate ($NaNO_3$).
Combustion Reaction
A combustion reaction is a rapid reaction, typically with oxygen ($O_2$), that produces heat and light. Complete combustion of hydrocarbons (compounds with C and H) produces carbon dioxide ($CO_2$) and water ($H_2O$).
General Formula (Hydrocarbon):
Visual Guide:
Example: Burning of Methane
Methane ($CH_4$), the primary component of natural gas, burns in oxygen to produce carbon dioxide and water.