100 mL of an aqueous HCl solution of pH =1 is mixed with V mL of a 0.025 M aqueous Ba(OH) ₂ solution. If the pH of the resulting mixture is 12 , the value of V is _____. (Nearest integer) Assume complete dissociation of both the acid and the base.

Step-by-step solution

For the HCl solution: pH = 1 [ H ^+] = 0.1 M Millimoles of H ^+ = 0.1 100 = 10 mmol For the Ba(OH) ₂ solution: Molarity of Ba(OH) ₂ = 0.025 M Since it is a strong diacidic base, [ OH ^-] = 2 0.025 = 0.05 M Millimoles of OH ^- = 0.05 V = 0.05V mmol For the final mixture: pH = 12 pOH = 14 - 12 = 2 [ OH ^-]_ final = 10⁻² M = 0.01 M Since the final solution is basic, OH ^- is in excess. The remaining millimoles of OH ^- after neutralization is: Excess OH ^- = 0.05V - 10 Total volume of the mixture = 100 + V mL The fina