You Can Investigate Diffusion in a Non-Living Syste,

Question 1

What is a phenolphthalein?

Answer 1

A pH indicator

Question 2

What can you use phenolphthalein to do?

Answer 2

Investigate diffusion in Agar jelly

Question 3

What do you do first?

Answer 3

Make up some Agar jelly with phenolphthalein and dilute sodium hydroxide - it will go pink

Question 4

What do you do second?

Answer 4

Fill a beaker with some dilute hydrochloric acid. Using a scalpel, cut a few cubes from jelly and put in beaker of acid

Question 5

What do you do last?

Answer 5

If you leave cubes for a while they’ll eventually turn colourless as acid diffuses into Agar jelly and neutralises sodium hydroxide

Question 6

How to Investigate rate of diffusion?

Answer 6

Using different sized cubes of Agar jelly and timing how long it takes for each cube to go colourless, cube with largest surface area to volume ratio loses colour quickest