Ionic Equilibrium Lecture Notes

A comprehensive set of vocabulary flashcards covering theories of acids and bases, pH concepts, buffers, salt hydrolysis, and solubility products based on the provided engineering chemistry lecture notes.

Arrhenius Acid

A substance which releases $H^+$ ions in $H_2O$.

Arrhenius Base

A substance which releases $OH^-$ ions in $H_2O$.

Bronsted-Lowry Acid

A species that acts as an $H^+$ ion donor.

Bronsted-Lowry Base

A species that acts as an $H^+$ ion acceptor.

Conjugate acid-base pair

A pair which differs by only one $H^+$ ion.

Amphiprotic substances

Species which can donate as well as accept $H^+$ ions.

Aprotic substances

Species that are neither donors nor acceptors of $H^+$ ions.

Lewis Acid

An electron-pair ($e^- \text{-pair}$) acceptor.

Lewis Base

An electron-pair ($e^- \text{-pair}$) donor.

Ostwald's dilution law

A law applicable for weak electrolytes only ($W.A$ & $W.B$) where the degree of dissociation is given by $\alpha = \sqrt{\frac{K}{C}}$.

Ionic product of water ($K_w$)

The product $[H^+][OH^-]$, which equals $1 \times 10^{-14}\,mol^2/lt^2$ at $25^\circ\text{C}$. Its value increases as temperature increases.

pH scale at $25^\circ\text{C}$

A scale where $0$ is acidic, $7$ is neutral, and $14$ is basic; defined by the relationship $pH + pOH = pK_w$.

Simple buffer

Salts of a Weak Acid ($W.A$) and a Weak Base ($W.B$) that act as a buffer solution.

Acid buffer

A mixed buffer consisting of a Weak Acid ($W.A$) and its salt with a Strong Base ($S.B$).

Basic buffer

A mixed buffer consisting of a Weak Base ($W.B$) and its salt with a Strong Acid ($S.A$).

Henderson's equation (Acid buffer)

The equation $pH = pK_a + \log\frac{[\text{Salt}]}{[\text{Acid}]}$ used to calculate the pH of an acid buffer.

Buffer capacity (\phi)

The number of moles of $S.A$ (or) $S.B$ added to $1\,litre$ buffer divided by the change in pH.

Cationic hydrolysis

Hydrolysis occurring in salts of a Strong Acid ($S.A$) and a Weak Base ($W.B$), resulting in an acidic solution.

Anionic hydrolysis

Hydrolysis occurring in salts of a Weak Acid ($W.A$) and a Strong Base ($S.B$), resulting in a basic solution.

Indicators

Weak organic acids and bases that indicate the point of equivalence in a titration by changing color.

Solubility product ($K_{sp}$)

The equilibrium constant for sparingly soluble salts, calculated for an $A_xB_y$ salt as $K_{sp} = x^x \cdot y^y \cdot S^{x+y}$ where $S$ is solubility.

Common-Ion effect

The phenomenon where the solubility of sparingly soluble salts decreases due to the presence of an ion already in the solution.