Chemical Reactions Calculator

Theoretical Yield Calculator

function calculateTheoreticalYield() { var reactantMass = parseFloat(document.getElementById("reactantMass").value); var reactantMolarMass = parseFloat(document.getElementById("reactantMolarMass").value); var productMolarMass = parseFloat(document.getElementById("productMolarMass").value); var reactantCoefficient = parseFloat(document.getElementById("reactantCoefficient").value); var productCoefficient = parseFloat(document.getElementById("productCoefficient").value); if (isNaN(reactantMass) || isNaN(reactantMolarMass) || isNaN(productMolarMass) || isNaN(reactantCoefficient) || isNaN(productCoefficient) || reactantMass <= 0 || reactantMolarMass <= 0 || productMolarMass <= 0 || reactantCoefficient <= 0 || productCoefficient <= 0) { document.getElementById("result").innerHTML = "Please enter valid positive numbers for all fields."; return; } // Step 1: Calculate moles of limiting reactant var molesReactant = reactantMass / reactantMolarMass; // Step 2: Use stoichiometric ratio to find moles of product var molesProduct = molesReactant * (productCoefficient / reactantCoefficient); // Step 3: Calculate theoretical yield of product in grams var theoreticalYield = molesProduct * productMolarMass; document.getElementById("result").innerHTML = "

Theoretical Yield: " + theoreticalYield.toFixed(4) + " g

"; }

Understanding Theoretical Yield in Chemical Reactions

The theoretical yield is a fundamental concept in chemistry, representing the maximum amount of product that can be formed from a given amount of reactants, assuming the reaction goes to completion with 100% efficiency and no losses. It's a calculated value based on the stoichiometry of a balanced chemical equation.

What is Stoichiometry?

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between reactants and products in chemical reactions. It's based on the law of conservation of mass, which states that matter cannot be created or destroyed. A balanced chemical equation provides the molar ratios (stoichiometric coefficients) between all substances involved in the reaction.

How to Calculate Theoretical Yield:

To calculate the theoretical yield, you typically follow these steps:

1. Balance the Chemical Equation: Ensure the number of atoms for each element is the same on both sides of the reaction.
2. Identify the Limiting Reactant: This is the reactant that will be completely consumed first, thereby limiting the amount of product that can be formed. Our calculator assumes you've already identified this.
3. Convert Mass of Limiting Reactant to Moles: Use the molar mass of the limiting reactant to convert its given mass into moles.
4. Use Stoichiometric Ratios: From the balanced equation, use the ratio of the stoichiometric coefficients between the limiting reactant and the desired product to find the moles of product that can be formed.
5. Convert Moles of Product to Mass: Use the molar mass of the product to convert the calculated moles of product into its theoretical mass (grams).

Example: Photosynthesis Reaction

Consider the simplified photosynthesis reaction where glucose (C₆H₁₂O₆) and oxygen (O₂) are produced from carbon dioxide (CO₂) and water (H₂O):

6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂

Let's say we start with 10.0 grams of CO₂ (our limiting reactant) and want to find the theoretical yield of O₂.

• Mass of Limiting Reactant (CO₂): 10.0 g
• Molar Mass of Limiting Reactant (CO₂): 12.01 (C) + 2 * 16.00 (O) = 44.01 g/mol
• Molar Mass of Desired Product (O₂): 2 * 16.00 (O) = 32.00 g/mol
• Stoichiometric Coefficient of Reactant (CO₂): 6
• Stoichiometric Coefficient of Product (O₂): 6

Using the calculator with these values:

1. Moles of CO₂ = 10.0 g / 44.01 g/mol ≈ 0.2272 mol
2. Moles of O₂ = 0.2272 mol CO₂ * (6 mol O₂ / 6 mol CO₂) ≈ 0.2272 mol O₂
3. Theoretical Yield of O₂ = 0.2272 mol * 32.00 g/mol ≈ 7.2704 g

The calculator would show a theoretical yield of approximately 7.2704 g of O₂.

This calculator simplifies the process by allowing you to input the necessary values directly, providing a quick way to determine the theoretical yield for any balanced chemical reaction.