This is a multiple answers question.Why was dichloromethane chosen as the organic solvent to be used for the extraction of caffeine from water?Group of answer choicesDichloromethane is not miscible with water.Dichloromethane has a higher solubility for caffeine than water at room temperature, i.e. 20oC.Dichloromethane has a higher solubility for caffeine than hot water.Dichloromethane is more dense than water.

To extract caffeine, a No Doz® tablet (10 g each) was crushed and added to 100 mL of distilled water and boiled for ten minutes. Suspended solids were removed, and the supernatant was transferred to a separatory funnel. Next, 100 mL of dichloromethane (DCM, density = 1.33 g/cm³) was added to the separatory funnel, and the mixture was shaken, which resulted in the formation of two layers. Each layer was separately collected, and the aqueous layer was poured back into the separatory funnel for the extraction to be repeated. One hundred mL of DCM was added to the separatory funnel, and a second extraction was performed. After the second extraction, the layers containing caffeine from both extractions were mixed together. The resulting solution was boiled gently until a white solid formed. To determine how much caffeine was expected to dissolve in each layer and how much caffeine was extracted in total, the following formulae were used to determine the partition coefficient (Ψ) of caffeine:Ψc = [Solute] in organic layer / [Solute] in aqueous layerEquation 1 Calculation of Ψ for an extractionΨa = Ï in organic layer / Ï in aqueous layerEquation 2 Approximation of Ψ for an extractionAfter completing the extraction, recrystallization was performed. Ethanol was added to the white solid, and the solution was gently warmed and allowed to cool down to 25°C. The solution was then placed on ice until crystals formed. The crystals were vacuum filtered and tested for purity via melting point determination, IR spectroscopy, and TLC plating. In the TLC procedure, DCM was used as the solvent system, and three spots were placed on the TLC plate: crude extract, recrystallized caffeine, and a pure caffeine sample.(Note: Ϊ is the solubility of a solute in a given solvent.)Question 36Which of the following is NOT a functional group present in caffeine? A.ImideB.AmideC.Primary amineD.Tertiary amine

The central nervous system stimulant caffeine can be extracted from commercial No Doz® tablets. Pure caffeine has a melting point of 235°C and a density of 1.23 g/cm3. The solubility of caffeine at standard temperature is 0.14 g/mL in dichloromethane and 0.02 g/mL in distilled water.Figure 1 CaffeineTo extract caffeine, a No Doz® tablet (10 g each) was crushed and added to 100 mL of distilled water and boiled for ten minutes. Suspended solids were removed, and the supernatant was transferred to a separatory funnel. Next, 100 mL of dichloromethane (DCM, density = 1.33 g/cm³) was added to the separatory funnel, and the mixture was shaken, which resulted in the formation of two layers. Each layer was separately collected, and the aqueous layer was poured back into the separatory funnel for the extraction to be repeated. One hundred mL of DCM was added to the separatory funnel, and a second extraction was performed. After the second extraction, the layers containing caffeine from both extractions were mixed together. The resulting solution was boiled gently until a white solid formed. To determine how much caffeine was expected to dissolve in each layer and how much caffeine was extracted in total, the following formulae were used to determine the partition coefficient (Ψ) of caffeine:Ψc = [Solute] in organic layer / [Solute] in aqueous layerEquation 1 Calculation of Ψ for an extractionΨa = Ï in organic layer / Ï in aqueous layerEquation 2 Approximation of Ψ for an extractionAfter completing the extraction, recrystallization was performed. Ethanol was added to the white solid, and the solution was gently warmed and allowed to cool down to 25°C. The solution was then placed on ice until crystals formed. The crystals were vacuum filtered and tested for purity via melting point determination, IR spectroscopy, and TLC plating. In the TLC procedure, DCM was used as the solvent system, and three spots were placed on the TLC plate: crude extract, recrystallized caffeine, and a pure caffeine sample.(Note: Ϊ is the solubility of a solute in a given solvent.)Question 37Following the procedure of the experiment, how much total caffeine could you expect to extract? A.6.50 gB.9.84 gC.11.72 gD.12.97 g

The central nervous system stimulant caffeine can be extracted from commercial No Doz® tablets. Pure caffeine has a melting point of 235°C and a density of 1.23 g/cm3. The solubility of caffeine at standard temperature is 0.14 g/mL in dichloromethane and 0.02 g/mL in distilled water.Figure 1 CaffeineTo extract caffeine, a No Doz® tablet (10 g each) was crushed and added to 100 mL of distilled water and boiled for ten minutes. Suspended solids were removed, and the supernatant was transferred to a separatory funnel. Next, 100 mL of dichloromethane (DCM, density = 1.33 g/cm³) was added to the separatory funnel, and the mixture was shaken, which resulted in the formation of two layers. Each layer was separately collected, and the aqueous layer was poured back into the separatory funnel for the extraction to be repeated. One hundred mL of DCM was added to the separatory funnel, and a second extraction was performed. After the second extraction, the layers containing caffeine from both extractions were mixed together. The resulting solution was boiled gently until a white solid formed. To determine how much caffeine was expected to dissolve in each layer and how much caffeine was extracted in total, the following formulae were used to determine the partition coefficient (Ψ) of caffeine:Ψc = [Solute] in organic layer / [Solute] in aqueous layerEquation 1 Calculation of Ψ for an extractionΨa = Ï in organic layer / Ï in aqueous layerEquation 2 Approximation of Ψ for an extractionAfter completing the extraction, recrystallization was performed. Ethanol was added to the white solid, and the solution was gently warmed and allowed to cool down to 25°C. The solution was then placed on ice until crystals formed. The crystals were vacuum filtered and tested for purity via melting point determination, IR spectroscopy, and TLC plating. In the TLC procedure, DCM was used as the solvent system, and three spots were placed on the TLC plate: crude extract, recrystallized caffeine, and a pure caffeine sample.(Note: Ϊ is the solubility of a solute in a given solvent.)Question 39Which of the following statements correctly describe the methods used in the experiment? I. The retention factor in a TLC procedure depends on the solvent system, temperature, and the adsorbent.II. A polar compound will exhibit a smaller retention factor on a normal phase TLC plate than a less polar compound.III. Anhydrous methanol has greater eluting strength than pentane when used as solvents in a TLC procedure. A.I onlyB.I and II onlyC.II and III onlyD.I, II, and III

The FDA considers caffeine a food additive and therefore it only has to be listed in the ingredient list.Group of answer choicesTrueFalse

Caffeine can safely be consumed in amounts greater than 500 mg/day.Group of answer choicesTrueFalse