Answer:
15.33
Explanation:
Given parameters:
Mass of KOH = 121g
Volume of solution = 100mL = 0.1dm³
Molar mass of KOH = 56.11g/mol
Unknown:
pH of the solution = ?
Solution:
To find the pH, we must first know the concentration of the solution obtained by mixing KOH up to this volume.
This can be done by finding the molarity of the solution.
Molarity = [tex]\frac{number of moles }{volume of solution}[/tex]
Number of moles of KOH = [tex]\frac{mass}{molar mass}[/tex] = [tex]\frac{121}{56.11}[/tex] = 2.16mole
Input parameters;
Molarity of solution = [tex]\frac{2.16}{0.1}[/tex] = 21.6moldm⁻³
KOH → OH⁻ + K⁺
21.6 21.6 21.6
In the solution we have 21.6moldm⁻³ of OH⁻ which is need to find the pH;
pOH = -log₁₀(OH⁻)
pOH = -log₁₀21.6
pOH = -1.33
Since pH + pOH = 14
pH = 14 - (-1.33) = 15.33
