#1 Free Chemical Reaction Calculator / Predictor 2025

This tool attempts to predict products for a limited set of common inorganic reactions by:

1. Parsing Reactants: Breaking down your input into individual chemical species and their elements.
2. Classifying Reactants: Identifying reactants as elements (metal, non-metal, halogen), acids, bases, ionic compounds (salts, oxides, hydroxides, carbonates, chlorates), water, etc.
3. Matching Reaction Patterns: Based on the types and number of reactants, it tries to match a known reaction pattern:
   • Combination (Synthesis): e.g., Metal + Non-metal → Salt.
   • Decomposition: e.g., Metal Carbonate → Metal Oxide + CO₂. (Often assumes heat is applied implicitly).
   • Single Displacement: Uses a simplified reactivity series. e.g., More reactive metal + Salt → Less reactive metal + New Salt.
   • Double Displacement (Metathesis): Uses simplified solubility rules to predict precipitates. e.g., Salt₁ + Salt₂ → Salt₃ + Salt₄ (one might be insoluble). Includes Acid-Base Neutralization.
4. Generating Products: Constructs the chemical formulas of likely products based on the matched pattern and common valencies/oxidation states.
5. Balancing: Once products are predicted, the full equation (reactants → products) is balanced using an algebraic method (similar to the separate Chemical Equation Balancer).

Important: Prediction is heuristic and rule-based for these common types. It doesn't involve quantum chemistry or extensive databases. Many reactions are more complex or have alternative products depending on conditions (temperature, pressure, concentration, catalysts) not considered here.

The predictor focuses on the following (with examples):

1. Combination (Synthesis):

• Metal + Non-metal → Binary Ionic Compound (e.g., 2 Na + Cl2 → 2 NaCl)
• Active Metal Oxide + Water → Metal Hydroxide (Base) (e.g., CaO + H2O → Ca(OH)2)
• Non-metal Oxide + Water → Oxyacid (e.g., SO3 + H2O → H2SO4)

2. Decomposition (assumes energy input like heat):

• Binary Compound → Elements (simple cases, e.g., 2 HgO → 2 Hg + O2)
• Metal Carbonate → Metal Oxide + CO₂ (e.g., CaCO3 → CaO + CO2)
• Metal Hydroxide → Metal Oxide + H₂O (e.g., Mg(OH)2 → MgO + H2O)
• Metal Chlorate → Metal Chloride + O₂ (e.g., 2 KClO3 → 2 KCl + 3 O2)

3. Single Displacement:

• Active Metal + Acid → Salt + H₂ (e.g., Zn + 2 HCl → ZnCl2 + H2)
• Active Metal + Water → Metal Hydroxide/Oxide + H₂ (e.g. 2Na + 2H2O → 2NaOH + H2)
• More Active Metal + Salt Solution → Less Active Metal + New Salt (e.g., Fe + CuSO4 → FeSO4 + Cu)
• More Active Halogen + Halide Salt → Less Active Halogen + New Halide Salt (e.g., Cl2 + 2 KBr → 2 KCl + Br2)

4. Double Displacement (Metathesis):

• Salt₁ + Salt₂ → Salt₃ + Salt₄ (predicts precipitate if one forms based on solubility rules) (e.g., AgNO3 + NaCl → AgCl(s) + NaNO3)
• Acid + Base → Salt + H₂O (Neutralization) (e.g., HCl + NaOH → NaCl + H2O)
• Acid + Carbonate/Bicarbonate → Salt + H₂O + CO₂ (e.g., 2 HCl + Na2CO3 → 2 NaCl + H2O + CO2)
• Acid + Sulfide → Salt + H₂S(g) (e.g. 2HCl + FeS → FeCl2 + H2S)

This list is not exhaustive, and predictions are based on typical outcomes.

For single displacement reactions, a simplified reactivity series is used:

Metals (most to least reactive):

Li > K > Ca > Na > Mg > Al > Zn > Fe > Ni > Sn > Pb > H > Cu > Hg > Ag > Pt > Au

(Metals above H can displace H from typical acids. Very reactive metals like Li, K, Ca, Na can displace H from cold water. Mg, Al, Zn, Fe can displace H from steam.)

Halogens (most to least reactive):

F2 > Cl2 > Br2 > I2

For predicting precipitates in double displacement reactions:

(s) will be appended to predicted insoluble products.

1. Enter Reactants:

• Type the chemical formulas of the reactants into the input field, separated by a plus sign (+).
• Example: Na + Cl2 or AgNO3 + NaCl or H2SO4 + Ba(OH)2.
• For decomposition reactions where there's typically one reactant, just enter that single reactant (e.g., KClO3 or CaCO3).
• Use standard chemical formulas (e.g., H2O, CO2, Al2(SO4)3). Elements are case-sensitive (e.g., 'Co' for Cobalt, 'CO' for Carbon Monoxide).
• Spaces are optional around the '+' sign.
• Do not include coefficients or an arrow (->) in the input. The tool will predict products and then balance.

2. Predict & Balance:

• Click the "Predict & Balance" button.

3. View Results:

• The tool will display:
  • The type of reaction it identified (e.g., "Single Displacement").
  • The full balanced chemical equation with the predicted products. Insoluble products in double displacement reactions may be marked with (s).
  • A step-by-step explanation of how the products were predicted and how the equation was balanced.
• If the input is invalid or the reaction type is not supported/predictable by this tool, an error message will appear.

4. Reset:

• Click the "Reset" button to clear the input field and results.

5. Explore Information:

• Click on the information bars to learn more about the prediction method, supported reactions, and the simplified rules used.