ICE Table Solver for Ka/Kb Chemistry

[H+] = --

What is the ICE Table Solver?

Quick Answer: An interactive tool that sets up and solves the Initial‑Change‑Equilibrium (ICE) table for a weak acid or weak base dissociation. Input initial concentration and the dissociation constant (Ka or Kb) to find equilibrium concentrations of all species and the pH/pOH.

Theory of ICE Tables and Weak Acids/Bases

For a weak acid HA ⇌ H+ + A−, the equilibrium expression is Ka = [H+][A−] / [HA]. If the initial concentration of HA is C and the change is −x, then at equilibrium:
[HA] = C − x, [H+] = x, [A−] = x.
Thus Ka = x2 / (C − x). The tool solves this quadratic equation for x (if Ka is not extremely small) or uses the approximation x = √(Ka C) if appropriate. Similarly, for a weak base with Kb, the same logic applies with OH−. The visual shows a bar chart comparing initial and equilibrium concentrations.

Step-by-Step Examples

Example 1: Acetic Acid (CH3COOH)

  1. Select "Weak Acid", C=0.1 M, Ka=1.8e-5. Click Solve.
  2. Equation: 1.8e-5 = x^2 / (0.1 - x). Solving gives x = [H+] = 1.33e-3 M, pH = 2.88.
  3. The ICE table displays initial, change, and equilibrium rows.

Example 2: Ammonia (Weak Base)

  1. Choose "Weak Base", C=0.1 M, Kb=1.8e-5.
  2. x = [OH-] = 1.33e-3 M, pOH = 2.88, pH = 11.12.
  3. The bar chart shows the small degree of dissociation.

Example 3: Using the Approximation

  1. If Ka is very small (e.g., 1e-10), the change x is negligible relative to C. The tool automatically applies the 5% rule and shows both exact and approximate results.

Frequently Asked Questions

What does the ICE table show?

The table lists the Initial concentrations, the Change in concentrations (using -x or +x), and the Equilibrium concentrations in terms of x. The solved value of x and final concentrations are displayed.

When is the approximation x << C valid?

If the percent dissociation is less than 5%, the approximation (x = sqrt(Ka*C)) is acceptable. The tool checks this and shows both methods.

Can I use this for strong acids?

Strong acids fully dissociate, so an ICE table with Ka is not needed. This tool is designed for weak acids and bases.

What units are the concentrations in?

Molarity (mol/L). The dissociation constant (Ka or Kb) is dimensionless in terms of concentrations, but has units of M if not simplified (though we treat it as dimensionless).

Does the tool handle polyprotic acids?

No, this ICE solver assumes monoprotic acids or mono‑base systems. Successive dissociations require more complex tables.