How do you make a titration curve?

Plot pH on the y-axis and the volume of titrant added on the x-axis. Choose the acid–base type and the tool computes the correct pH at each volume, marks the equivalence and half-equivalence points, shades the buffer region, and lets you export SVG or PNG — free.

What is the equivalence point on a titration curve?

The equivalence point is where the moles of titrant added exactly neutralize the moles of analyte — the midpoint of the steep vertical jump in pH. Its pH is 7 only for a strong acid–strong base titration; it is above 7 for a weak acid and below 7 for a weak base.

What is the half-equivalence point and how does it relate to pKa?

The half-equivalence point is halfway to the equivalence point. For a weak acid or base, the concentrations of the species and its conjugate are equal there, so by the Henderson–Hasselbalch equation the pH equals the pKa. The tool marks the half-equivalence point and its pH = pKa.

Why is the equivalence point of a weak acid titration above pH 7?

At the equivalence point of a weak acid–strong base titration, all the acid has been converted to its conjugate base, which is slightly basic and reacts with water to raise the pH above 7. For a weak base–strong acid titration the conjugate acid makes the equivalence point below 7.

What is the buffer region on a titration curve?

The buffer region is the relatively flat part of a weak acid or weak base curve before the equivalence point, where a mixture of the weak species and its conjugate resists pH change. It is centered on the half-equivalence point, where pH = pKa. The tool shades this region.

Is this titration curve generator free?

Yes. The Titration curve mode runs entirely in your browser, computes the curve from standard titration equations, and is free with no image credits used. Export a clean SVG or high-resolution PNG for lab reports, homework, and slides.

Chemistry Tool

Titration Curve Generator for Acid–Base Titrations

Generate an acid–base titration curve in seconds. Pick strong acid–strong base, weak acid–strong base, or weak base–strong acid; the tool plots the correct pH curve, marks the equivalence point and the half-equivalence point (pH = pKa), shades the buffer region, and exports SVG or PNG — free.

Strong & weak acid / base casesEquivalence & half-equivalence (pH = pKa)Buffer region shadedSVG & PNG export — free

Titration type

pKa4.75

The half-equivalence point sits at pH = pKa.

Title

Equivalence point at pH 8.7 (basic — typical of a weak acid).

Titration Curve Examples

Acid–base titration curves rendered by the exact engine

表示:

Strong Acid + Strong Base

A strong–strong titration has a sharp jump and an equivalence point at pH 7.

strong-acidstrong-base

Weak Acid + Strong Base

A weak acid shows a buffer region, half-equivalence at pH = pKa, and equivalence above pH 7.

weak-acidbufferpKa

Weak Base + Strong Acid

A weak base titrated with acid falls in pH, with the equivalence point below pH 7.

weak-basebuffer

Labeled Titration Curve

Every region labeled — initial, buffer, half-equivalence (pH = pKa), and equivalence.

labeledequivalence

Acetic Acid + NaOH

A real example: acetic acid (pKa 4.76) titrated with NaOH.

acetic-acidexample

Ammonia + HCl

Another example: ammonia (weak base) titrated with HCl — equivalence is acidic.

ammoniaexample

What is a titration curve?

A titration curve is a graph of pH versus the volume of titrant added during an acid–base titration. As titrant is added, the pH changes slowly at first, then jumps sharply at the equivalence point — where the moles of acid and base are stoichiometrically equal — before leveling off. The shape of the curve and the pH at the equivalence point depend on whether the acid and base are strong or weak.

The four regions of a titration curve

Initial pH: the pH of the analyte before any titrant is added.
Buffer region: for a weak acid or base, the pH rises gradually as a buffer of the species and its conjugate forms.
Equivalence point: the steep vertical jump where the acid and base have exactly neutralized; its pH is 7 only for a strong–strong titration.
After equivalence: the pH levels off as excess titrant dominates.

Strong vs weak acid and base titration curves

A strong acid–strong base titration has a sharp jump and an equivalence point at pH 7. A weak acid–strong base titration starts at a higher pH, has a clear buffer region, and an equivalence point above pH 7 (the conjugate base is basic). A weak base–strong acid titration falls in pH, with a buffer region and an equivalence point below pH 7. This tool draws the correct shape for each case.

The equivalence point and half-equivalence point

The equivalence point is where moles of titrant equal moles of analyte — the midpoint of the steep jump. The half-equivalence point (halfway to equivalence) is special for weak acids and bases: there the concentrations of the weak species and its conjugate are equal, so the pH equals the pKa. This is the easiest way to read a pKa off a titration curve, and the tool marks it for you.

How to read pKa from a titration curve

For a weak acid titrated with a strong base, find the equivalence point (the steep jump), then go to half that volume — the half-equivalence point. The pH there equals the pKa of the acid. The buffer region is centered on this point. Adjust the pKa in this generator to see the whole curve shift while the half-equivalence pH tracks the pKa exactly.

When to use the AI illustration mode

Use the exact Titration curve mode for correctly-placed acid–base curves. Switch to AI illustration for extras the template does not cover: a polyprotic acid curve with two equivalence points, an indicator color-change range shaded on the curve, or a picture of the titration apparatus (burette and flask) beside the graph.