A chemist conducted a recrystallization on 18.5 g of a solid and collected 12.5 g from the first, and 2.7 g from the second recrystallization. Show your calculation and answer the following questions:
What is the percent recovery in the first recrystallization? (1.5 marks)
What is the total percent recovery?
%recovery 1st = (12.5/18.5)*100 = ?
%recovery total = [(12.5+2.7)/18.5)]*100 = ?
To calculate the percent recovery for the first recrystallization, you need to divide the mass collected from the first recrystallization (12.5 g) by the original mass of the solid (18.5 g), and then multiply by 100 to obtain the percentage:
Percent Recovery = (Mass collected / Original mass) * 100
Using the given values:
Percent Recovery = (12.5 g / 18.5 g) * 100
Percent Recovery = 67.57%
Therefore, the percent recovery in the first recrystallization is 67.57%.
To calculate the total percent recovery, you need to consider the mass collected from both the first and second recrystallizations. Simply add the masses collected from each recrystallization and divide by the original mass, then multiply by 100 to obtain the percentage.
Total Percent Recovery = ((Mass collected from 1st recrystallization + Mass collected from 2nd recrystallization) / Original mass) * 100
Using the given values:
Total Percent Recovery = ((12.5 g + 2.7 g) / 18.5 g) * 100
Total Percent Recovery = (15.2 g / 18.5 g) * 100
Total Percent Recovery = 82.43%
Therefore, the total percent recovery is 82.43%.