Bromine will react with limonene according to this reaction (there's a picture, but I can't get that on here. So I'll do my best to write it out).
136.23 g/mol + Br2 ------> 296.04 g/mol
Suppose 627 mg of limonene was reacted with 3.7 mL of a 7.7% (v/v) solution of Br2 in dichloromethane (a solvent), and after purification, 921 mg of the brominated producted was isolated. What was the percent yield?
% yield: ________%
Please help me! I don't even know where to start this problem.
To determine the percent yield in this problem, we need to compare the actual yield (921 mg) to the theoretical yield. The theoretical yield is the maximum amount of product that can be obtained based on stoichiometry.
First, let's calculate the amount of Br2 reacted with the 3.7 mL solution. To do this, we need to convert mL to grams using the density of the solution. Let's assume the density of the 7.7% (v/v) solution of Br2 in dichloromethane is 1.49 g/mL.
Mass of Br2 = (volume of solution in mL) x (density of solution in g/mL)
= 3.7 mL x 1.49 g/mL
= 5.513 g
Next, let's calculate the number of moles of limonene used in the reaction. To do this, we need to convert the mass of limonene to moles using its molar mass.
Moles of limonene = (mass of limonene in mg) / (molar mass of limonene in g/mol)
= 627 mg / 136.23 g/mol
= 4.602 x 10^(-3) mol
According to the balanced chemical equation, one mole of limonene reacts with one mole of Br2. So, the number of moles of Br2 reacted is also 4.602 x 10^(-3) mol.
Now we can calculate the theoretical yield. From the balanced chemical equation, the molar ratio between limonene and the product is 1:1. Therefore, the molar mass of the product is also 296.04 g/mol.
Theoretical yield = (moles of limonene reacted) x (molar mass of the product)
= 4.602 x 10^(-3) mol x 296.04 g/mol
= 1.360 g
Finally, we can calculate the percent yield using the formula:
Percent yield = (actual yield / theoretical yield) x 100
= (921 mg / 1360 mg) x 100
= 67.87%
Therefore, the percent yield of the reaction is approximately 67.87%.