Medium⏱ time45 min$ cost5
DIY Acid Test
Use a cabbage indicator to count drops and compare how strong different acids are.
Start building ↓
Result first
The build
Step 01
Set the base
Put coloured indicator with a little base in a cup.
Step 02
Add acid by drops
Drip an acid in, counting drops.
Step 03
Find the change
Stop when the colour flips to acidic.
Step 04
Compare acids
Repeat for each acid and compare drop counts.
Working Principle
Each drop of acid neutralises a bit of the base; the colour change marks the point where they balance, so fewer drops means a stronger acid.
The science behind it
A closer look
This DIY titration estimates relative acid strength by how much is needed to reach the neutral colour point.
Take it further
Variables to test
- 1 Rank vinegar, lemon and soda by drops needed.
- 2 Dilute one acid — how do drop counts change?
More Chemistry
Chemistry
Lemon Battery Array
Wire lemons with zinc and copper electrodes in series to light a real LED from fruit.
Easy⏱25 min$6
Chemistry
Reaction Volcano
Baking soda and vinegar erupt on cue while you measure how the ratio changes the blast.
Easy⏱30 min$7
Chemistry
Elephant Toothpaste
A catalyst makes hydrogen peroxide erupt in a giant foam column in seconds.
Medium⏱20 min$8