Consider the titration of a 25.0-mL sample of 0.115 M RbOH with 0.100 M HCl. Determine each quantity. a. the initial pH d. the pH at the equivalence point e. the pH after adding 5.0 mL of acid beyond the equivalence point

Verified step by step guidance

1. Step 1: Calculate the initial pH of the RbOH solution. Since RbOH is a strong base, it dissociates completely in water. Use the concentration of RbOH to find the hydroxide ion concentration, [OH^-], and then calculate the pOH. Finally, convert pOH to pH using the relation pH + pOH = 14.
2. Step 2: Determine the volume of HCl needed to reach the equivalence point. At the equivalence point, the moles of HCl added will equal the moles of RbOH initially present. Use the initial concentration and volume of RbOH to find the moles of RbOH, and then use the concentration of HCl to find the volume of HCl required.
3. Step 3: Calculate the pH at the equivalence point. At the equivalence point, the solution contains only water and the salt RbCl, which does not affect the pH. Therefore, the pH is neutral, which is 7.0 at 25°C.
4. Step 4: Calculate the moles of HCl added beyond the equivalence point. Use the additional volume of HCl added (5.0 mL) and its concentration to find the moles of excess HCl.
5. Step 5: Determine the pH after adding 5.0 mL of acid beyond the equivalence point. The excess HCl will determine the pH. Calculate the concentration of H^+ ions from the excess HCl in the total volume of the solution, and then find the pH using the formula pH = -\log[H^+].