Exercise 13 Calculating Ka from Percent Dissociation Lactic acid (HC3H5O3) is a waste product that accumulates in muscle tissue during exertion, leading to pain and a feeling of fatigue. In a 0.100 aqueous solution, lactic acid is 3.7% dissociated. Calculate the M of for this acid. Ka 1.4 × 10−4 Ka= Determination of the pH of a weak base is very similar to the determination of the pH of a weak acid. Follow the same steps. Remember, however, that is the [OH−] and taking the negative log of will x x give you the and not the pH! pOH Exercise 14 The pH of Weak Bases I Calculate the pH for a 15.0 solution of NH3 (Kb = 1.8 × 10−5). M pH = 12.20
Exercise 13 Calculating Ka from Percent Dissociation Lactic acid (HC3H5O3) is a waste product that accumulates in muscle tissue during exertion, leading to pain and a feeling of fatigue. In a 0.100 M aqueous solution, lactic acid is 3.7% dissociated. Calculate the of Ka for this acid. Ka= 1.4 × 10−4 Determination of the pH of a weak base is very similar to the determination of the pH of a weak acid. Follow the same steps. Remember, however, that x is the [OH−] and taking the negative log of x will give you the pOH and not the pH! Exercise 14 The pH of Weak Bases I Calculate the pH for a 15.0 M solution of NH3 (Kb = 1.8 × 10−5). pH = 12.20