Discover why cells are so small!
In this student led investigation, students are given agar cubes of three different sizes, impregnated with indicator to display an alkaline pH. Initial measurements make it clear that the surface-area-to-volume ratio is large for small cubes, with the ratio reducing as cube size increases.
Using bromothymol blue as the pH indicator with vinegar as the acid this offers a safer alternative to other common methods.
- 8 x 1 cm cube
- 8 x 1.5 cm cube
- 8 x 2.5 cm cube