Chemistry
Limiting Reagent Concentration Calculator
Compare two solution reactants by reaction extent, calculate yield-adjusted product concentration, and reconcile excess-reactant concentrations.
Moles of reagent A-
Moles of reagent B-
Reaction extent available from A (mol)-
Reaction extent available from B (mol)-
Limiting reaction extent (mol)-
Theoretical product amount (mol)-
Yield-adjusted product amount (mol)-
Approximate mixed volume (L)-
Expected product concentration (mol/L)-
Unreacted A concentration (mol/L)-
Unreacted B concentration (mol/L)-
Decision view
Dual reagent scales, limiting extent gate, and mixture composition
Dual reagent scales, limiting extent gate, and mixture compositionA and B are normalized by their own coefficients before the shorter extent rail sets product and leftover concentrations.
Exact scenario comparisonReagent B volume (mL) changes while all other entered assumptions remain constant.
| Reagent B volume (mL) | Moles of reagent A | Moles of reagent B | Reaction extent available from A (mol) | Reaction extent available from B (mol) | Limiting reaction extent (mol) | Theoretical product amount (mol) | Yield-adjusted product amount (mol) | Approximate mixed volume (L) | Expected product concentration (mol/L) | Unreacted A concentration (mol/L) | Unreacted B concentration (mol/L) |
|---|
How to use Limiting Reagent Concentration Calculator
- Enter both solution amounts.
- Use a verified balanced equation.
- Review both normalized extent rails before interpreting product.
Calculator guide
Understanding Limiting Reagent Concentration Calculator
The limiting reagent is found only after every reactant amount is divided by its own balanced coefficient. Raw molarity, volume, or mole count alone can identify the wrong limit.
Detailed calculation process
Detailed limiting-reagent concentration calculation
The default mixes 120 mL of 0.8 M A with 50 mL of 1.5 M B for 2A+B→2P.
General formula: n_A=C_A V_A/1000n_B=C_B V_B/1000ξ_A=n_A/ν_Aξ_B=n_B/ν_Bξ=min(ξ_A,ξ_B)n_P=ξν_P yC_P=n_P/V_mixC_i,left=(n_i-ξν_i)/V_mix Reaction extent puts both reagents on the same stoichiometric basis. The smaller value controls product and consumption.
What each symbol means
Worked substitution with the default inputs
A limits the default mixture; expected product is about 0.5195 M and leftover B about 0.1588 M.
Worked situations
Practical examples
- The default A provides 0.048 mol of reaction extent.
- B provides 0.075 mol, so A limits and the 92%-yield product concentration is about 0.5195 M.
Better inputs
Useful tips
- Adjust concentrations for reagent assay.
- Measure mixture volume for systems with meaningful contraction.
- Keep conversion and isolated yield distinct in rigorous work.
Before relying on the result
Limitations and common mistakes
- Volumes are assumed additive.
- Reaction completion, equilibrium, side products, purity, and phase behavior are not modeled.
- Yield reduces product but does not alter the leftover-reactant ledger.
Reference
Key terms
- Coefficient-normalized amount
- Reactant moles divided by its stoichiometric coefficient.
- Excess reagent
- Reactant remaining after the limiting extent is consumed.
- Mixed volume
- Approximate sum of the two entered solution volumes.
Important note
Use a balanced equation, verified concentrations, actual phase volumes, conversion data, purity, and safety controls for real reactions.
Frequently asked questions
Can the higher-molarity reagent be limiting?
Yes, if its volume or coefficient-normalized amount is smaller.
Why is A leftover zero in the default case?
A supplies the smaller extent and is consumed by the modeled complete reaction.
Does isolated yield create leftover reactant?
Not necessarily; product loss during isolation differs from incomplete conversion.