Introduction to Acids and Bases - AP Chemistry

A Lewis base is an electron pair donor. Provides an electron pair to an acceptor.

$pH = -\text{log}_{10} [H^+]$. Negative logarithm of hydrogen ion concentration.

The common ion is $OH^-$. Present in all aqueous base solutions.

$K_w = 1.0 \times 10^{-14}$ at 25°C. Product of $[H^+]$ and $[OH^-]$ concentrations.

$HCl$ is stronger than $HF$. $HCl$ is a strong acid, $HF$ is weak.

$K_w$ increases with temperature. Higher temperature increases ion product.

The conjugate base of $H_2SO_4$ is $HSO_4^-$. Loses one proton from diprotic acid.

A Brønsted-Lowry acid is a proton donor. Gives up $H^+$ to another species.

$K_w = [H^+][OH^-]$. Autoionization equilibrium expression for water.

$pK_b = -\text{log}_{10} K_b$. Negative logarithm of base dissociation constant.

$pH = 2$. Strong acid completely ionizes: $pH = -\log(0.01)$.

$pH = 11$. Strong base: $pOH = 3$, so $pH = 14 - 3$.

A weak base partially dissociates in solution. Incomplete dissociation in aqueous solution.

The common ion is $H^+$. Present in all aqueous acid solutions.

$K_a = \frac{[H^+][A^-]}{[HA]}$. Equilibrium expression for acid dissociation.

The conjugate base of $HCl$ is $Cl^-$. Loses a proton to form the conjugate base.

$pOH = 4$. Calculated using $pOH = -\log[OH^-]$.

Increasing $[H^+]$ decreases pH. pH decreases as acidity increases.

$NaOH$ is stronger than $NH_3$. $NaOH$ is strong, $NH_3$ is weak.

Increasing $[OH^-]$ decreases pOH. pOH decreases as basicity increases.

$pK_a = -\text{log}_{10} K_a$. Negative logarithm of acid dissociation constant.

The pH of pure water is 7. Neutral because $[H^+] = [OH^-]$.

$pOH = -\text{log}_{10} [OH^-]$. Negative logarithm of hydroxide ion concentration.

$pH + pOH = 14$ at 25°C. Based on the ion product of water.

Acidic solutions have a pH less than 7. Higher $[H^+]$ than $[OH^-]$.

A Lewis acid is an electron pair acceptor. Receives an electron pair from a donor.

$pH = 3$. Calculated using $pH = -\log[H^+]$.

An acid increases $[H^+]$ in aqueous solution. Releases hydrogen ions when dissolved.

A strong base completely dissociates in solution. 100% dissociation in aqueous solution.