A chemistry student wants to determine the percentage of ethanol in a sample of wine. The student takes a 50 mL aliquot of the wine, dries it, and finds the weight of the residual solids to be 0.325 g. The student then distills the rest of the wine, evaporates the distillate to dryness, and finds the weight of the residue to be 2.324 g. Using mass balance calculations, what is the percentage of ethanol in the wine sample?

Question

A chemistry student wants to determine the percentage of ethanol in a sample of wine. The student takes a 50 mL aliquot of the wine, dries it, and finds the weight of the residual solids to be 0.325 g. The student then distills the rest of the wine, evaporates the distillate to dryness, and finds the weight of the residue to be 2.324 g. Using mass balance calculations, what is the pe

Answer 1

To determine the percentage of ethanol in the wine sample, we need to calculate the mass of ethanol and then divide it by the total mass of the wine sample.First, let's find the mass of the wine sample. We know the mass of the residual solids  0.325 g  and the mass of the residue after distillation  2.324 g . The mass of the wine sample can be calculated as follows:Mass of wine sample = Mass of residual solids + Mass of residue after distillationMass of wine sample = 0.325 g + 2.324 gMass of wine sample = 2.649 gNow, we need to find the mass of ethanol in the wine sample. Since the residue after distillation is the mass of the ethanol, we can use this value:Mass of ethanol = 2.324 gFinally, we can calculate the percentage of ethanol in the wine sample:Percentage of ethanol =  Mass of ethanol / Mass of wine sample  * 100Percentage of ethanol =  2.324 g / 2.649 g  * 100Percentage of ethanol  87.7%Therefore, the percentage of ethanol in the wine sample is approximately 87.7%.