General Chemistry 2: Acids and Bases

Lactic acid, HC$_3$H$_5$O$_3$, is a waste product that accumulates in muscle 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 value of K$_a$ for this reaction.

Compare the concentration of H$_3$O$^+$ in 1 M and 2 M solutions of HC$_2$H$_3$O$_2$, K$_a$ = 1.8 x 10$^{-5}$. (doubling the concentration results in an increase of hydronium ions by what factor?)

Calculate the pH of a mixture of equal parts 2.0 M HF and 1.0 M HOCl. Also find the concentration of OCl$^-$ and F$^-$ ions in the solution. The K$_a$ of HF = 7.2 x 10$^{-4}$, K$_a$ of HOCl = 3.5 x 10$^{-8}$

Calculate the pH of 0.1 M NH$_4$Cl. The K$_b$ of NH$_3$ = 1.8 x 10$^{-5}$

Calculate the pH of 0.12 M KNO$_2$. The K$_a$ of HNO$_2$ = 4.0 x 10$^{-4}$

Find the pH of a 0.1 M solution of NH$_3$. If 50 ml of this solution is titrated by 50 ml of 0.1 M HCl, find the pH at the equivalence point. (K$_a$ = 5.56 x 10$^{-10}$ )