Calculate the maximum amount of product that can form from a chemical reaction
1 Limiting Reagent → 1 Product
Unit: mol
Unit: g/mol
The theoretical yield calculator determines the maximum amount of product that can form in a chemical reaction under perfect conditions. It uses stoichiometry to convert moles of limiting reagent to moles and mass of product, assuming 100% conversion with no side reactions or losses.
Moles of Product
nproduct = (nlimiting / a) × b
Mass of Product
mass = nproduct × Mproduct
Given Reaction
2H₂ + O₂ → 2H₂O
Limiting reagent: 3.0 mol Hâ‚‚
Identify Coefficients
Hâ‚‚ coefficient (a) = 2
Hâ‚‚O coefficient (b) = 2
Calculate Moles of Product
nH₂O = (3.0 mol / 2) × 2 = 3.0 mol
Convert to Mass
mass = 3.0 mol × 18.015 g/mol = 54.045 g H₂O
Theoretical yield: 54.045 grams
Using excess reagent instead
Always base calculations on limiting reagent
Ignoring stoichiometric ratios
Must account for coefficients in balanced equation
Wrong molar mass
Use correct molecular formula and atomic masses
Confusing with actual yield
Theoretical is maximum; actual is what you get
Find which reactant limits the reaction
Calculate reaction efficiency
Calculate molecular weight from formula
Theoretical yield is the maximum amount of product that can be produced from a given amount of reactants, assuming perfect conditions: 100% conversion, no side reactions, and no losses during purification or transfer.
Real reactions rarely achieve 100% efficiency due to incomplete reactions, side reactions forming unwanted products, reversible reactions reaching equilibrium, and physical losses during product isolation and purification.
Yes, theoretical yield is always calculated from the limiting reagent (the reactant that is completely consumed first). If you have multiple reactants, determine which is limiting before calculating theoretical yield.
Sum the atomic masses of all atoms in the molecular formula using the periodic table. For example, Hâ‚‚O = 2(1.008) + 15.999 = 18.015 g/mol. Use atomic masses to at least 3 decimal places for accuracy.
Calculate theoretical yield for each product separately using its stoichiometric coefficient from the balanced equation. Each product will have its own theoretical yield based on the limiting reagent.
No, theoretical yield represents 100% conversion (the maximum possible). If your actual yield exceeds theoretical yield, there's an error in your calculations or measurements, possibly contamination or incomplete drying.
Industries use theoretical yield for process planning, cost estimation, and efficiency monitoring. Comparing actual to theoretical yield (percent yield) helps optimize reactions and identify process improvements.
Percent yields vary widely: simple reactions may achieve 70-95%, while complex multi-step syntheses often yield 30-60%. Yields above 90% are excellent, while below 50% may indicate the need for optimization.
Education
Stoichiometry problems and lab reports
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Industry
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Research
Synthetic method development and comparison