Chemistry · Chapter 14

Ka, Kb and Percent Ionization

Dial a strength and a concentration. The curve is computed from the exact quadratic, so you can watch percent ionization climb while the pH climbs too.

Live curve switch what the y axis shows

Percent ionization and pH against concentration

Controls

Jump to a real one

Where you are standing

2.88pH acidic
Ionized amount x: 1.33e-3 mol/L
Percent ionized: 1.33 percent
Left un-ionized: 9.87e-2 mol/L
pH: 2.88   pOH: 11.12

The conjugate partner

Your constant: Ka = 1.8e-5
Partner constant: Kb = 5.6e-10
Product: 1.0e-14  (that is Kw)
pK sum: 14.00

Weaken the acid and its conjugate base gets stronger. The product is locked, so one side can only grow when the other shrinks.

Exact against the shortcut

Shortcut x = √(KC): 1.34e-3
Exact x from the quadratic: 1.33e-3
Error in the shortcut: 0.7 percent
Verdict: shortcut is fine

Drag the concentration far left and watch the shortcut fall apart.