Aim: To make acid-base indicators using everyday substances.
Equipment: Red cabbage, a beaker, water, tripod, Bunsen burner, gauze mat, 1.0 mol L-1 NaOH.
Method: Chop the cabbage into small pieces until you have enough to fill 2 cups. Place the cabbage in a large beaker and add water to cover the cabbage. Boil over a Bunsen burner for at least ten minutes for the colour to leach out of the cabbage. Filter out the plant material to obtain a red-purple-bluish coloured liquid. This liquid is at about pH 7. (The exact colour you get depends on the pH of the water.) Place in a small beaker and leave to one side.
Discussion: My group experimented on red cabbage. The acid made the indicator red. And the base made the indicator green. The acid and base mix with the indicator and it forms a different colour, warning you whether it is acidic or neutral/basic.
Conclusion: We successfully made acid-base indicators by mixing acids and bases in with the indicator.
No comments:
Post a Comment
Note: only a member of this blog may post a comment.