How do you find the pH of this?
2) If you titrate 5mL of a 1.5M NaOH solution into 25mL of 2.0M HCl, what is the pH?
2) If you titrate 5mL of a 1.5M NaOH solution into 25mL of 2.0M HCl, what is the pH?
Just Me
Favorite Answer
5 x 1.5 M = 7.5 mmoles of NaOH
25 x 2.0M = 50mmoles of HCl
50-7.5 = 42.5 mmoles of HCl left in 30mL of solution = 1.41 M
HCl
pH = -log(H+) = -log 1.41 = -0.15 (The pH is negative)
Dr.A
Moles NaOH = 0.005 L x 1.5 M = 0.0075
Moles HCl = 0.025 L x 2.0 = 0.050
Moles HCl in excess = 0.050 - 0.0075 =0.0425
total volume = 30 mL = 0.030 L
Molarity of HCl = 0.0425 / 0.030 L =1.4
pH = - log 1.4 =0.15