Self-Ionisation of Water (Leaving Cert Chemistry): Flashcards

Process where water dissociates to form $\text{H}^+$ and $\text{OH}^-$ ions

$\text{H}^+$ (hydrogen) and $\text{OH}^-$ (hydroxide)

Ionic product of water

$K_w = [\text{H}^+][\text{OH}^-]$

$1.0 \times 10^{-14}$

$1.0 \times 10^{-7}$ M

$1.0 \times 10^{-7}$ M

$K_w$ increases with temperature

Endothermic, $\Delta H = +55.8$ kJ mol$^{-1}$

$1.0 \times 10^{-7}$ M

Greater than $1.0 \times 10^{-7}$ M

Less than $1.0 \times 10^{-7}$ M

Inverse: one increases, other decreases

Always equals $K_w$ at that temperature