Limiting Reagent Calculator
Identify the limiting reactant and calculate excess reactant left over in a chemical reaction.
Calculation Parameters
Specify your stoichiometry inputs.
Calculated Result
Expert Tip
Ensure units are correctly formatted (e.g. Kelvin for gas temperatures and liters for volumes) to get chemically accurate outputs.
How this Calculator Works
This calculator determines the limiting reactant in a chemical reaction by comparing the available moles of reactants to their stoichiometric coefficients. Adjust the parameters using the sliders below:
- Reactant A Moles: Available moles of the first reactant (Default: 2)
- Coefficient A: Stoichiometric coefficient of reactant A (Default: 2)
- Reactant B Moles: Available moles of the second reactant (Default: 3)
- Coefficient B: Stoichiometric coefficient of reactant B (Default: 1)
The results are computed instantly and updated in the results panel on the right.
Formula & Methodology
Where:
- Reactant Moles: The quantity of reactant available in moles.
- Coefficient: The stoichiometric multiplier from the balanced chemical equation.
Step-by-Step Calculation Example
To determine the limiting reagent for a reaction represented by $2A + B \rightarrow Products$ with 2 moles of A and 3 moles of B, follow these steps:
- Identify the input parameters. For example:
- Reactant A Moles = 2, Coefficient A = 2
- Reactant B Moles = 3, Coefficient B = 1
- Apply the formula:
Calculate ratios: - Ratio A = 2 mol / 2 = 1.0 - Ratio B = 3 mol / 1 = 3.0 Compare ratios: - Since 1.0 < 3.0, Reactant A is the limiting reagent.
- Verify the calculated value which is updated instantly in the results panel on the right.
Frequently Asked Questions
What is a limiting reagent? ▼
The limiting reagent is the reactant that is completely consumed first in a chemical reaction, limiting total product formed.
How do you find the limiting reactant? ▼
Calculate theoretical product yield from each reactant starting mass; the reactant that yields the smallest product quantity is limiting.
What is an excess reactant? ▼
An excess reactant is a starting reagent that remains unreacted after the limiting reactant has been completely consumed.