Answer:
The pH of the solution is approximately : 1.05
Given data :
volume of HCl = 68.00 mL = 0.068 L
concentration of HCl = 0.280 M
Volume of NaOH = 60 mL = 0.6 L
concentration of NaOH = 0.125 M
Determine the pH of the solution
First step : determine the number of mol of HCl and NaOH
mol of HCl = 0.068 * 0.280 = 0.0190 mol HCl
mol of NaOH = 0.06 * 0.125 = 0.0075 mol NaOH volume of
excess moles of H⁺ after reaction = 0.0190 - 0.0075 = 0.0115 mol
Next step : determine the pH value of the solution
Total volume of solution = 0.068 + 0.060 = 0.128
concentration of the solution [ H⁺ ] = excess moles / total volume
= 0.0115 / 0.128 = 0.0898
Therefore
pH = - log [ H⁺ ]
= - log ( 0.0898 ) = 1.047 ≈ 1.05
Hence we can conclude that The pH of the solution is approximately : 1.05 .
