Presentation on theme: "Titration Calculations Weak Acid and Strong Base."— Presentation transcript:
Titration Calculations Weak Acid and Strong Base
In titrations of weak acids or bases, there are two steps involved Step 1: Stoichiometry of the acid/base reaction Step 2: Weak acid or base equilibrium problem
Example Hydrogen cyanide (HCN), a powerful respiratory inhibitor, is highly toxic. It is a very weak acid (K a = 6.2 x 10 -10 ) when dissolved in water. If a 50.0 mL sample of 0.100 M HCN is titrated with 8.00mL of 0.100 M NaOH a) calculate the number of moles of HCN remaining in the solution b) calculate the molar concentration of CN - in the solution c) calculate the pH of the solution d) calculate the volume of NaOH that must be added to reach the equivalence point e) what will the pH be like at the equivalence point
Example A chemist has synthesized a monoprotic acid and wants to determine the K a value. The chemist dissolves 2.00 mmole of the solid acid in 100.0 mL water and titrates the resulting solution with 0.0500M NaOH. After 20.0mL NaOH has been added, the pH is 6.00. What is the value of the K a?