What is the limiting reagent in synthesis of Triphenylmethanol?

Determine the quantities of bromobenzene, magnesium metal, and methyl benzoate needed to prepare a theoretical yield of 9.65g of triphenylmethanol. Methyl benzoate should be your limiting reagent; use 10% more than the stoichiometric quantity of Mg and 15% more than the stoichiometric quantity of bromobenzene.

Using this Grignard reagent, triphenylmethanol can be synthesized in a two-step reaction first adding the reagent and then adding an acid. The Grignard reagent attack the electrophilic carbonyl carbon of the benzophenone and pushed electrons up to the oxygen.

Furthermore, what is the theoretical yield of Triphenylmethanol? To calculate the percent yield of triphenylmethanol, you divide the actual yield by the theoretical yield and multiply by 100.

Also, what is the limiting reagent for the Grignard reaction in our procedure?

Since the magnesium is limiting reagent, so the number of mole of Grignard reagent produced is limited by number of mole of magnesium. Since the Grignard reagent is excess, the product is limited by methyl benzoate so that it is limiting reagent in the reaction.

What is Triphenylmethanol used for?

Triphenylmethanol is used as a reagent in the research laboratory. It acts as an intermediate in the production of the commercially useful triarylmethane dyes. It is used in the preparation of triphenylmethane. It is also used as an antiproliferative agent.

Why is Grignard exothermic?

The resulting “Grignard reagent” acts as both a good nucleophile and a strong base. Its nucleophilic character allows it to react with the electrophilic carbon in a carbonyl group, thus forming the carbon-carbon bond. Formation of the Grignard reagent is highly exothermic.

Why is Triphenylmethanol insoluble in water?

Triphenylmethanol (below) is insoluble in water, but when it is treated with concentrated sulfuric acid, it dissolves to create a bright yellow solution. Protonation of the carbinol gives a very unstable oxonium ion (because the triphenylmethyl cation formed after loss of water is so stabilized by resonance).

Why are Grignard reactions important?

The Grignard reaction (pronounced /gri?ar/) is an organometallic chemical reaction in which alkyl, allyl, vinyl, or aryl-magnesium halides (Grignard reagent) add to a carbonyl group in an aldehyde or ketone. This reaction is important for the formation of carbon–carbon bonds.

What is the purpose of the Grignard reaction experiment?

The purpose of this experiment was to reduce the carbonyl-containing compound benzophenone to the alcohol compound trimethylmethanol. This reduc- tion was done by the nucleophilic addition of the Grignard reagent: phenyl magnesium bromide, in a nonreactive ethyl ether solution.

How is biphenyl formed in a Grignard reaction?

Biphenyl is formed via coupling of two phenyl radicals. The radicals are produced by homolytic bond cleavage of the C-Br bond in bromobenzene in the presence of Mg metal. Coupling of the phenyl radical with [MgBr] radical leads to formation of the Grignard reagent.

What reagent can be used to convert benzophenone into Triphenylmethanol?

Phenylmagnesium bromide will be used to produce either benzoic acid (reaction with CO2; dry ice) or triphenylmethanol when reacted with benzophenone (or ethyl benzoate).

How do you make Phenylmagnesium bromide?

Preparation of phenylmagnesium bromide: Place 2 g of magnesium turnings and 15 ml of anhydrous ether in a dry round-bottom flask. The necessary elements are coupled for reflux under anhydrous conditions and with the addition of reagents (see Figure 4.14 in p. 101).

How do you remove biphenyl from a Grignard reaction?

In order to remove the biphenyl, add 0.5 mL of petroleum ether to the residue, cool in an ice bath briefly while stirring and remove the solvent (process is called trituration). The remaining residue (the crude triphenylmethanol) should then be recrystallized from 2-propanol.

Why does water ruin the Grignard reaction?

q Diethyl ether is an especially good solvent for the formation of Grignard reagents because ethers are non-acidic (aprotic). Water or alcohols would protonate and thus destroy the Grignard reagent, because the Grignard carbon is highly nucleophilic. This would form a hydrocarbon.

How do I calculate theoretical yield?

How to Calculate Theoretical Yields Determine the number of moles of each reactant. Multiply the molecular weight by the number of moles in the equation. Calculate the theoretical mole yield by using the chemical equation. Multiply the number of moles of the product by the molecular weight of the product to determine the theoretical yield.

How Is percent yield calculated?

To express the efficiency of a reaction, you can calculate the percent yield using this formula: %yield = (actual yield/theoretical yield) x 100. A percent yield of 90% means the reaction was 90% efficient, and 10% of the materials were wasted (they failed to react, or their products were not captured).

Can you calculate percent yield using moles?

Calculating Percent Yield Multiply the expected moles of the product by its molar mass. For example, the molar mass of HF is 20 grams. Therefore, if you expect 4 moles of HF, the theoretical yield is 80 grams. Divide the actual yield of the product by the theoretical yield and multiply by 100.

What is the white precipitate that forms when benzophenone is added to your Grignard solution?

bromobenzene in anhydrous ether. To this reagent, an anhydrous ether solution of benzophenone is added. When the reaction is complete (~30 min), the product will be subjected to an aqueous work-up whereby triphenylmethanol appears as a white precipitate.

Why is biphenyl soluble in petroleum ether but Triphenylmethanol is not?

Synthetically, it also can be allowed to react with carbon dioxide to give carboxylic acids and with oxygen to give hydroperoxides: A high reaction temperature favors the formation of this product. Biphenyl is highly soluble in petroleum ether, and it is easily separated from triphenylmethanol.