How Do You Calculate Theoretical Yield

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Theoretical Yield Calculator

Calculate the maximum amount of product from a chemical reaction

Reactant Data

Product Data

Calculation Results:

How to Calculate Theoretical Yield

Theoretical yield is the maximum amount of product that can be generated from a specific amount of limiting reactant in a chemical reaction. It assumes 100% efficiency and no side reactions.

The Step-by-Step Formula

To calculate theoretical yield, follow these mathematical steps:

  1. Find Moles of Reactant: Divide the mass of the limiting reactant by its molar mass.
  2. Apply Molar Ratio: Multiply the moles of reactant by the ratio of (Product Coefficient / Reactant Coefficient) from the balanced equation.
  3. Convert to Mass: Multiply the moles of product by the molar mass of that product.
Formula:
Theoretical Yield (g) = [Mass of Reactant / Molar Mass of Reactant] × [Product Coefficient / Reactant Coefficient] × Molar Mass of Product

Practical Example

Imagine you are reacting 10g of Salicylic acid (Molar Mass: 138.12 g/mol) to produce Aspirin (Molar Mass: 180.16 g/mol) in a 1:1 ratio.

  • Moles of Reactant: 10g / 138.12 g/mol = 0.0724 moles.
  • Molar Ratio: 1/1 = 1.
  • Theoretical Yield: 0.0724 moles × 180.16 g/mol = 13.04g.

If you actually produce 10g in the lab, your Percent Yield would be (10 / 13.04) × 100 = 76.6%.

function calculateYield() { var massR = parseFloat(document.getElementById('massReactant').value); var mmR = parseFloat(document.getElementById('molarMassReactant').value); var cR = parseFloat(document.getElementById('coeffReactant').value); var mmP = parseFloat(document.getElementById('molarMassProduct').value); var cP = parseFloat(document.getElementById('coeffProduct').value); var resultBox = document.getElementById('yieldResultBox'); var yieldOutput = document.getElementById('yieldOutput'); var molesOutput = document.getElementById('molesOutput'); if (isNaN(massR) || isNaN(mmR) || isNaN(cR) || isNaN(mmP) || isNaN(cP) || mmR <= 0 || cR <= 0) { alert("Please enter valid positive numeric values for all fields."); return; } // Step 1: Calculate moles of limiting reactant var molesR = massR / mmR; // Step 2: Use stoichiometry ratio to find moles of product var molesP = molesR * (cP / cR); // Step 3: Convert product moles to mass var theoreticalYield = molesP * mmP; // Display Results yieldOutput.innerHTML = "Theoretical Yield: " + theoreticalYield.toFixed(4) + " grams"; molesOutput.innerHTML = "Calculated Moles of Product: " + molesP.toFixed(5) + " mol"; resultBox.style.display = "block"; }

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