What is the limiting reactant in a Grignard reaction?
The limiting reagent in a Grignard reaction is usually the substance to which you add the Grignard reagent, but you have to confirm this by calculation.
Assume that, in a preparation of triphenylmethanol, you prepared phenylmagnesium bromide by reacting 2.1 mL of bromobenzene (density 1.50 g/mL) with 0.50 g of magnesium in anhydrous ether. To this, you then slowly added a solution of 2.4 g benzophenone in anhydrous ether. What was the limiting reactant?
The equations (
Calculate the moles of each reactant
Identify the limiting reactant
All theoretical molar ratios are 1:1.
Since benzophenone has the fewest moles, it is the limiting reactant.