Ammonia is a weak base and nitric acid is a strong acid. Will methyl red be used?DrJohn said:Ammonia solution is not a strong base...
What is the pH of ammonia, nitric acid and ammonium nitrate (the end product)
Check the pH that phenolphthalien changes colour at.
What colour will it show in the ammonia solution?
What colour will it show at the end point of the titration?
That would depend on the pH around the equivalence point.haha0p1 said:Ammonia is a weak base and nitric acid is a strong acid. Will methyl red be used?
This is a two mark question. Can you tell how we will approach questions like this one.Mayhem said:That would depend on the pH around the equivalence point.
So this is a homework question. How do you like this idea: Try to perform a titration of a strong acid with ammonia solution. Monitor the entire titration with a pH meter. Find the inflection point pH. Making a graph might be needed. Now find a table of pH indicators and choose an indicator which has a color transition as near to the pH inflection point found, as you can find.haha0p1 said:This is a two mark question. Can you tell how we will approach questions like this one.
I could use some correction in case my thinking is wrong, but I would tend to agree here, to use phenolphthalein. Color change is at pH above 7 (but I not sure; I should really look-up this information). Full neutralization of ammonia would be at something above pH 7.haha0p1 said:Homework Statement:: Suggest a suitable indicator to find the end-points of the reaction below:
0.0500 mol/dm³ nitric acid and 0.0500 mol/dm³ aqueous ammonia.
Relevant Equations:: Acid + Base = Salt + Water
This question is asking about finding the indicator. I think phenolphthalein will be used as there is a reaction between strong acid and strong base. Is this approach to the question correct? Or am I missing any important concept? Kindly tell
An acid-base indicator is a substance that changes color in response to a change in pH, allowing one to determine the endpoint of a titration. These indicators are typically weak acids or bases themselves and exhibit different colors in their protonated and deprotonated forms.
To choose the right indicator, you need to know the pH range over which your titration's endpoint occurs. The indicator should have a color change range that falls within the pH range of the equivalence point of your titration. Common indicators include phenolphthalein (pH 8.2-10.0) and methyl orange (pH 3.1-4.4).
The equivalence point is the stage in the titration when the amount of titrant added is chemically equivalent to the amount of substance being titrated. The chosen indicator should have a color change range that includes the pH of the equivalence point to ensure accurate determination of the endpoint.
Yes, in some complex titrations, using more than one indicator can be beneficial. This approach can provide a more precise determination of the endpoint by covering a broader pH range or confirming the endpoint with multiple color changes.
Common indicators and their pH ranges include:- Phenolphthalein: pH 8.2-10.0 (colorless to pink)- Methyl orange: pH 3.1-4.4 (red to yellow)- Bromothymol blue: pH 6.0-7.6 (yellow to blue)- Litmus: pH 4.5-8.3 (red to blue)- Thymol blue: pH 1.2-2.8 (red to yellow) and pH 8.0-9.6 (yellow to blue)