Reaction Types Lab
Identify and compare all five major reaction types in chemistry. Watch animated molecular rearrangements, verify atom conservation with bar charts, and record observations across multiple trials.
Guided Experiment: Classifying Chemical Reactions
Before running each reaction, predict what type of pattern you expect: will atoms combine, break apart, swap partners, or burn?
Write your hypothesis in the Lab Report panel, then click Next.
2Na + Cl₂ → 2NaCl
Press Run to animate the molecular rearrangement.
Controls
Reaction Details
| Element | Reactants | Products | Match |
|---|---|---|---|
| Cl | 1 | 2 | |
| Na | 2 | 2 |
Sodium metal burns in chlorine gas to form sodium chloride (table salt).
Atom Conservation Chart
Solid bars show reactant atom counts; dashed bars show product counts. In a balanced equation, every pair must match.
Data Table
(0 rows)| # | Trial | Reaction Type | Equation | Balanced | Precipitate |
|---|
Reference Guide
Five Reaction Types
Every chemical reaction can be classified into one of five types based on how reactants and products are arranged.
- Synthesis — two or more substances combine into one
- Decomposition — one compound breaks into two or more
- Single replacement — one element displaces another
- Double replacement — two compounds exchange ions
- Combustion — hydrocarbon burns with O₂ to give CO₂ + H₂O
Synthesis & Decomposition
Synthesis follows the pattern A + B → AB. Multiple reactants combine to form a single product.
Decomposition is the reverse: AB → A + B. One compound breaks apart into simpler products. Electrolysis of water and thermal decomposition of carbonates are classic examples.
These two types are mirror images of each other in terms of reactant and product counts.
Replacement Reactions
In single replacement (A + BC → AC + B), a free element displaces another element from a compound. The reaction only occurs if the displacing metal is higher in the activity series.
In double replacement (AB + CD → AD + CB), two ionic compounds exchange partners. The reaction is driven by forming a precipitate, a gas, or water.
Combustion
Complete combustion of a hydrocarbon always produces carbon dioxide and water. The general form is:
CₓHᵧ + O₂ → CO₂ + H₂O
To balance, first set carbon (equals number of C atoms), then hydrogen (H₂O count), then oxygen last (may require fractional coefficient, then multiply through).