Respuesta :
Answer:
a) 18.81% is the mass percent (m/m) of the KCl solution.
b) 3.643 M is the molarity of the KCl solution.
c) 0.6073 M is the molarity of the diluted KCl solution.
Explanation:
a) mass on of evaporating dish = 24.10 g = x
mass on of evaporating dish and KCl solution = 44.30 g = y
After heating, mass on of evaporating dish and dry KCl = 27.90 g = z
Mass of KCl solution = y - x = 44.30 g - 24.10 g = 20.2 g
Mass of KCl in solution = z - x = 27.90 g - 24.10 g = 3.8 g
The mass percent (m/m) of the KCl solution;
[tex]=\frac{\text{Mass of KCl}}{\text{Mass of KCL solution}}\times 100[/tex]
[tex]=\frac{3.8 g}{20.2 g}\times 100=18.81\%[/tex]
18.81% is the mass percent (m/m) of the KCl solution.
b) Moles of KCl = [tex]\frac{3.8 g}{74.5 g/mol}=0.05101 mol[/tex]
Volume of the KCl solution = 14.0 mL = 0.014 L ( 1 mL = 0.001 L)
Molarity of the solution :
[tex]\frac{0.05101 mol}{0.014 L}=3.644 M[/tex]
3.643 M is the molarity of the KCl solution.
c)
Molarity of KCl solution before dilution = [tex]M_1=3.644 M[/tex]
Volume of the solution before dilution = [tex]V_1=10 mL[/tex]
Molarity of KCl solution after dilution = [tex]M_2=?[/tex]
Volume of the solution after dilution = [tex]V_2=60.0 mL[/tex]
[tex]M_1V_1=M_2V_2[/tex]
[tex]M_2=\frac{M_1V_1}{V_2}=\frac{3.644M\times 10.0 mL}{60.0mL}=0.6073 M[/tex]
0.6073 M is the molarity of the diluted KCl solution.
