Calculator Inputs
Choose the reaction pattern, substrate traits, medium, and reagent behavior. Then calculate to rank common mechanism families using a weighted educational model.
Example Data Table
These examples show how the calculator compares reaction environments and predicts the most likely pathway family.
| Case | Reaction Family | Substrate | Key Conditions | Predicted Major Mechanism |
|---|---|---|---|---|
| 1 | Alkyl Halide | Primary | Strong nucleophile, polar aprotic, low sterics | SN2 |
| 2 | Alkyl Halide | Tertiary | Strong bulky base, heat, good leaving group | E2 |
| 3 | Carbonyl Compound | Aldehyde | Anionic nucleophile, moderate sterics | Nucleophilic Addition |
| 4 | Aromatic Ring | Aryl | Electrophile and acid catalyst present | Electrophilic Aromatic Substitution |
| 5 | Alkane | Secondary C-H site | Radical initiation and halogenation setup | Free Radical Substitution |
Formula Used
This calculator uses a weighted heuristic model rather than a single closed-form chemistry equation. Each input contributes pathway points to the major mechanism families.
Mechanism Score = Reaction Family Weight + Substrate Weight + Leaving Group Weight + Nucleophile Weight + Base Weight + Solvent Weight + Temperature Weight + Steric Weight + Carbocation Weight + Reagent Style Weight + Radical Weight
Relative Likelihood (%) = (Mechanism Score / Sum of Positive Scores) × 100
Confidence (%) is based on the top pathway share and the score gap above the runner-up pathway.
This method is designed for education, screening, and revision. It does not replace full kinetic, thermodynamic, spectroscopic, or experimental analysis.
How to Use This Calculator
- Select the overall reaction family first.
- Choose the substrate class that best matches the reacting center.
- Set leaving group quality, nucleophile strength, and base strength.
- Choose solvent type, temperature, and steric hindrance level.
- Estimate carbocation stability from resonance and substitution trends.
- Pick the reagent style that best represents your reaction setup.
- Enable radical initiation only when chain conditions are present.
- Click calculate to view the dominant mechanism, score table, and graph.
FAQs
1. What does this calculator predict?
It predicts the most likely broad reaction mechanism family from common organic options such as SN1, SN2, E1, E2, electrophilic addition, nucleophilic addition, electrophilic aromatic substitution, and free radical substitution.
2. Is the result exact for real laboratory reactions?
No. It is an educational decision model. Real reactions also depend on concentration, specific reagents, conformations, catalysts, competing equilibria, and experimental details beyond this simplified scoring system.
3. Why can two mechanisms score closely?
Some substrates, especially secondary centers, genuinely sit between competing pathways. The calculator shows this competition through close scores, runner-up labels, and moderate or low confidence values.
4. How does solvent affect the result?
Polar protic solvents tend to stabilize ions and help SN1 or E1. Polar aprotic solvents often enhance direct nucleophilic attack, making SN2 or nucleophilic addition more competitive.
5. Why does steric hindrance matter so much?
Crowding blocks backside attack and weakens SN2. The same crowding can shift outcomes toward E2, SN1, or E1 when the rest of the conditions also support those pathways.
6. Can this help with aromatic chemistry?
Yes. When the reaction family is aromatic and electrophilic conditions are chosen, the calculator increases the score for electrophilic aromatic substitution and explains the pathway logic.
7. What does the confidence score mean?
Confidence reflects how dominant the top pathway is compared with the full score distribution and how far it sits above the runner-up mechanism. Higher confidence means clearer mechanistic separation.
8. Can I export the result?
Yes. After calculation, use the CSV button for spreadsheet-friendly data or the PDF button for a printable report containing the result summary, input summary, and mechanism score table.