Weak electrolyte

Mnemonic for speed

• Negative Negative Positive Positive: \( X^{+} + H_2O \rightleftharpoons XOH + H^{+} \) \( X^{-} + H_2O \rightleftharpoons HX + OH^{-} \)

Unimportant Procedure 1

\( \frac{v_{postive}}{v_{negative}} = \frac{K}{Q} \)

Proof for example

\( 2NO_2 (g) = 2NO (g) + O_2 (g) \) \( v_{postive} = k_{postive} c^2(NO_2) \) \( v_{negative} = k_{negative} c^2(NO) \cdot c(O_2) \) When balanced, \( v_{postive} = v_{negative} \) \( \frac{k_{postive}}{k_{negative}} = \frac{c^2(NO) \cdot c(O_2)}{c^2(NO_2)} = K \) Other times, \( \frac{v_{postive}}{v_{negative}} = \frac{k_{postive}}{k_{negative}} \cdot \frac{c^2(NO_2)}{c^2(NO) \cdot c(O_2)} = \frac{K}{Q} \)

\( K_h \)

\( K_h = \frac{K_w}{K_a} \)

Proof:

\( K_h = \frac{c(HA) \cdot c(OH^-)}{c(A^-)} = \frac{c(HA) \cdot c(OH^-) \cdot c(H+)}{c(A^-) \cdot c(H+)} = \frac{K_w}{K_a} \)

NCEE