Answer:
12.875
Explanation:
Balanced equation of the reaction:
HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l)
mole of acid = mole of base
75 × 0.150 = volume of base needed × 0.3
volume of base needed = 37.5 ml
excess OH = 0.3 × 37.5 ml / 150 ml where total volume = 75 ml + 75 ml = 150 ml
excess OH = 0.075 M
pOH = - log (OH⁻) = - log (0.075 M) = 1.125
pH + pOH = 14
pH = 14 - pOH = 14 - 1.125 = 12.875
