Grignard Reaction Stoichiometry Calculator

Summary

Enter amounts and molecular weights for your Grignard reagent and electrophile to find moles, limiting reagent, and theoretical product mass.

How it works

1. Enter the mass (or volume + density) and molecular weight of your Grignard reagent (RMgX).
2. Enter the mass (or volume + density) and molecular weight of the electrophile (e.g., ketone, aldehyde, ester).
3. Optionally enter the molecular weight of the expected product.
4. Enter stoichiometric coefficients if your reaction is not 1:1.
5. Click Calculate to see moles, limiting reagent, excess amount, and theoretical yield.

Use cases

• Plan a Grignard addition to a ketone or aldehyde before running the reaction.
• Determine how many equivalents of Grignard reagent you have relative to the electrophile.
• Calculate theoretical product mass for nucleophilic addition reactions.
• Optimize reagent ratios to minimize waste of expensive Grignard reagents.
• Verify stoichiometry in undergraduate and graduate organic chemistry labs.
• Scale Grignard reactions up from milligram to gram scale while keeping ratios correct.

Frequently Asked Questions