Question

A one-liter solution of 0.7 M KCl (74 g/mol) is evaporated and 10 g of KCl are recovered. What is the percent recovery of KCl?

a. 10%
b. 13.5%
c. 15%
d. 20%

Answer 1

To calculate the percent recovery of KCl, we need to find the mass of the recovered KCl and compare it to the initial mass of KCl in the solution. The percent recovery of KCl is approximately 19.31%, which is closest to option d. 20%.

Step-by-step explanation:

To calculate the percent recovery of KCl, we need to find the mass of the recovered KCl and compare it to the initial mass of KCl in the solution.

Initial moles of KCl = initial concentration x initial volume

Initial moles of KCl = 0.7 M x 1 L = 0.7 moles

Mass of initial KCl = initial moles x molar mass

Mass of initial KCl = 0.7 moles x 74 g/mol = 51.8 g

Percent recovery = (recovered mass / initial mass) x 100%

Percent recovery = (10 g / 51.8 g) x 100% = 19.31%

Therefore, the percent recovery of KCl is approximately 19.31%, which is closest to option d. 20%.