Answer:
There must be added 19.63 grams of hexachlorophene
Explanation:
<u>Step 1: </u>Data given
hexachlorophene has a molar mass of 406.9 g/mole
mass of chloroform = 125 grams
Boiling point of the solution = 62.60 °C
Kb Chloroform = 3.63 °C*kg/mol
Boiling point chloroform = 61.20 °C
<u>Step 2:</u> Calculate change of temperature
ΔT = 61.20 - 62.60 °C = -1.4 °C
<u>Step 3</u>: Calculate molality
-1,4 °C = mass * Kb
-1.4 °C = m * 3.63 °C/molal
m= 0.386 mol/Kg
<u>Step 4:</u> Calculate number of moles
0.386 mole/kg = moles solute / 0.125 Kg
moles solute = 0.386 moles/Kg * 0.125 Kg = 0.04825 moles
<u>Step 5:</u> Calculate mass
mass = 0.04825 moles * 406.9 g/mole =19.63 grams
There must be added 19.63 grams of hexachlorophene