Theoretical Yield Calculator

How to Calculate Theoretical Yield

Calculating the theoretical yield is a fundamental skill in chemistry that helps predict the maximum amount of product that can be formed in a chemical reaction. This calculator simplifies the process, but understanding the underlying concepts is crucial.

What is the Formula?

The formula for calculating theoretical yield is:

\[ \text{Theoretical Yield (moles)} = \text{Limiting Reagent (moles)} \times \text{Stoichiometric Ratio} \]

\[ \text{Theoretical Yield (grams)} = \text{Theoretical Yield (moles)} \times \text{Molar Mass of Product (g/mol)} \]

Where:

• Limiting Reagent is the reactant that will be completely consumed in the reaction
• Stoichiometric Ratio is the ratio of product to limiting reagent in the balanced equation
• Molar Mass is the mass of one mole of the product

What are the calculation steps?

1. Identify the limiting reagent in the reaction
2. Calculate the moles of limiting reagent
3. Determine the stoichiometric ratio between the product and the limiting reagent
4. Calculate the theoretical yield in moles by multiplying the moles of limiting reagent by the stoichiometric ratio
5. Convert the theoretical yield from moles to grams by multiplying by the molar mass of the product

Example Calculation

Let's calculate the theoretical yield of water (H₂O) from the reaction of hydrogen (H₂) and oxygen (O₂):

2 H₂ + O₂ → 2 H₂O

Given:

• Limiting reagent (H₂): 4 grams
• Molecular weight of H₂: 2.02 g/mol
• Stoichiometric ratio (H₂O:H₂): 1:1
• Molecular weight of H₂O: 18.02 g/mol

Step 1: Calculate moles of limiting reagent (H₂)

Moles of H₂ = 4 g ÷ 2.02 g/mol = 1.98 moles

Step 2: Calculate theoretical yield in moles

Theoretical Yield (moles) = 1.98 moles × 1 = 1.98 moles H₂O

Step 3: Convert to grams

Theoretical Yield (grams) = 1.98 moles × 18.02 g/mol = 35.68 grams H₂O

Therefore, the theoretical yield of water is 35.68 grams.

Diagram of Theoretical Yield

The following diagram illustrates the concept of theoretical yield:

This diagram shows the relationship between theoretical yield (entire green area) and actual yield (solid green area). The theoretical yield represents the maximum possible product, while the actual yield in real reactions is often less due to various factors like incomplete reactions or side products.