CHEM1011 Lecture Notes - Lecture 28: Equilibrium Constant, Acid Dissociation Constant, Weak Base

Determining lonic Strength Part A Unlike strong acids and bases that ionize completely in solution, weak acids or bases partially ionize. The tendency to ionize (i.e., the ionic strength) of a weak acid or base can be quantified in several ways including Pyridine is a weak base that is used in the manufacture of pesticides and plastic resins It is also a component of cigarette smoke. Pyridine ionizes in water as follows The pK, of pyridine is 8.75. What is the pH of a 0.400 M solution of pyridine? Express the pH numerically to two decimal places Hints and percent ionization pH- Submit My Answers Give Up Part B Benzoic acid is a weak acid that has antimicrobial properties. Its sodium salt, sodium benzoate, is a preservative found in foods, medications, and personal hygiene products. Benzoic acid dissociates in water: The pKa of this reaction is 4.2. In a 0.70 M solution of benzoic acid, what percentage of the molecules are ionized? Express the percentage numerically using two significant figures Hints percent ionized = Submit My Answers Give Up

▼ Part A Pyridine is a weak base that is used in the manufacture of pesticides and plastic resins. It is also a component of cigarette smoke. Pyridine ionizesi Unlike strong acids and bases that ionize completely in solution weak acids or bases partially ionize. The tendency of a weak acid or base to ionize can be quantified in several ways including follows The pK, of pyridine is 8.75. What is the pH of a 0.220 M solution of pyridine? (Assume that the temperature is 25 C.) Express the pH numerically to two decimal places. Aa or Ab pKa or pKb e and percent ionization View Available Hint(s) This assumes that species of equal concentrations are being compared as percent ionization is affected by concentration. pH Submit Part B Benzoic acid is a weak acid that has antimicrobial properties. Its sodium salt, sodium benzoate, is a preservative found in foods, medications, and p hygiene products. Benzoic acid ionizes in water: The pK of this reaction is 4.2. In a 0.51 M solution of benzoic acid, what percentage of the molecules are ionized? Express your answer to two significant figures and include the appropriate units. View Available Hint(s)