Discussion Overview
The discussion revolves around identifying an appropriate indicator for an acid-base titration involving nitric acid and ammonia solution. Participants explore the implications of using different indicators based on the nature of the acid and base involved, focusing on the pH at which these indicators change color.
Discussion Character
- Homework-related
- Debate/contested
- Exploratory
Main Points Raised
- Some participants propose using phenolphthalein as the indicator due to the reaction between a strong acid (nitric acid) and a weak base (ammonia).
- Others argue that ammonia is not a strong base and raise questions about the pH of ammonia, nitric acid, and the resulting ammonium nitrate.
- There are inquiries about the color change of phenolphthalein in ammonia solution and at the endpoint of the titration.
- Some participants suggest that methyl red might be a suitable indicator, depending on the pH around the equivalence point.
- A later reply discusses the necessity of determining the inflection point pH through experimental titration and suggests using a pH meter and graphing the results to select an appropriate indicator.
- One participant expresses uncertainty about the color change of phenolphthalein and suggests verifying the pH range for its color transition.
Areas of Agreement / Disagreement
Participants do not reach a consensus on which indicator is most suitable, as multiple competing views regarding the use of phenolphthalein and methyl red are presented. The discussion remains unresolved regarding the best approach to selecting an indicator for this specific titration.
Contextual Notes
Participants mention the need to consider the pH at the equivalence point and the specific color change ranges of the indicators discussed. There is also a suggestion to verify the pH values associated with the indicators before making a final decision.