Based on the amounts given in the laboratory procedure, which starting material - Mg, bromobenzene or benzophenone - is the limiting reagent? Show your work.
The limiting reagent in the formation of the Grignard reagent and Triphenylmethanol is benzophenone. To determine the limiting reagent, we need to compare the amounts of the starting materials, namely Mg, bromobenzene, and benzophenone, based on the given laboratory procedure. Let's break down the calculations step by step.
Calculating the Moles of Each Starting Material
Molar Mass:
- Molar mass of bromobenzene (C6H5Br) = 157.01 g/mol
- Molar mass of benzophenone (C13H10O) = 182.22 g/mol
For Bromobenzene:
- Mass = 6.4 g
- Moles = Mass / Molar Mass = 6.4 g / 157.01 g/mol = 0.0408 mol
For Benzophenone:
- Mass = 7.2 g
- Moles = Mass / Molar Mass = 7.2 g / 182.22 g/mol = 0.0396 mol
Comparison of Moles
After calculating the moles of each starting material, we find that the number of moles of bromobenzene is slightly higher than benzophenone. Since the reaction requires equal stoichiometric amounts of both starting materials, the limiting reagent is the one that is present in a smaller amount. In this case, benzophenone is the limiting reagent.
In conclusion, benzophenone is the limiting reagent in the formation of the Grignard reagent and Triphenylmethanol based on the given amounts in the laboratory procedure.