Hard Practice — Advanced Set

Quick Recap — Multi-step Equilibrium & pH (Hard)

• Weak acid: $[H^+]=\sqrt{K_a C}$, $\alpha=\sqrt{K_a/C}$; buffer $pH=pK_a+\log\dfrac{[salt]}{[acid]}$.
• Mixing strong acid + base: find excess $[H^+]$ or $[OH^-]$, then pH.
• $K_{sp}$: convert between solubility and $K_{sp}$ ($AB\to s^2$, $A_2B/AB_2\to4s^3$); common ion sets $[X]$.
• Very dilute strong acid ($\le10^{-6}$ M): water's $H^+$ matters, so pH is just under 7.