References
[I use red cabbage to make pH indicator. The pH solution from 2 to 13.] 1. pH=2 100ml distilled water + 1ml HCL 2. pH=4 100ml distilled water + 0.1g apple acid 3. pH=5.5 100ml distilled water + 2g H3BO3(Boric acid) 4. pH=7 100ml distilled water 5. pH=8 100ml distilled water + 0.5g NaHCO3 6. pH=11 700ml distilled water + 1ml NaOH 7. pH=12 250ml distilled water + 1ml NaOH 8. pH=13 100ml distilled water + 1ml NaOH
Next step: 1. Rate of colour change 2. Reversibility of colour change