simple-spectro

Very cheap, autonomous and precise spectrophotometer for DIY biology and chemistry.

This project is maintained by Hackuarium

pH determination attempts

First try

To start, we needed values for different pH solution, we had:

From these we made 12 solutions from pH 1 to 10 (increase by one), 12 and 14. Then add 4ml of each solution in tanks and add 10 drops of red cabbage in each tank.

NB: from each initial solution we filled as many as possible tanks to obtain means of absorption. We obtained from 3 to 8 tanks for each pH.

If you want to see all these measures, please look at:

Second try

Using the same stock solutions as before, and a pH-meter, we were able to make different solutions, with a precise pH. In each tank, we put 4 mL of acidic or basic solution and 5 drops of red cabbage solution. Plotting the absorbance in function of the pH, we obtained the following graph:

Here you can find the values we used:

Third try

We made a new red cabbage solution, same concentration but this time with distilled water. In each tank we placed 4 ml of acidic or basic solution and again 5 drops of our re cabbage solution. Here is the plot od the absorbance in function of the pH:

Here you can find the values we used: