Can use phenolptalein on titration with HNO3 acid, NAOH base
Yes, phenolphthalein can be used as an indicator for titration involving HNO3 acid and NaOH base. Phenolphthalein is a commonly used pH indicator that changes color depending on the pH of the solution.
To perform the titration, you will need the following materials and equipment:
1. Phenolphthalein indicator
2. HNO3 solution
3. NaOH solution
4. Burette
5. Flask
6. Distilled water
7. Pipette
8. White tile or background
Here's a step-by-step procedure for performing the titration:
1. Start by preparing your NaOH solution. Fill the burette with the NaOH solution and ensure you record the initial volume.
2. Take a measured volume (usually around 10 mL) of the HNO3 solution using a pipette and transfer it to a flask.
3. Add a few drops of phenolphthalein indicator to the flask containing the HNO3 solution. Phenolphthalein in its acidic form is colorless.
4. Slowly start adding the NaOH solution from the burette into the flask while swirling the flask continuously. The NaOH will react with the HNO3, and as the acid is neutralized, the pH of the solution will gradually increase.
5. Continue adding the NaOH solution until you observe a permanent color change in the solution. Phenolphthalein starts to turn pink or magenta in an alkaline environment with a pH around 8.2-10. The pink color indicates that all the HNO3 has reacted with NaOH and the solution is now slightly basic.
6. As soon as you see the color change, stop adding the NaOH solution and record the final volume of NaOH solution used from the burette.
7. Repeat the experiment multiple times to ensure accuracy and obtain consistent results.
To calculate the concentration of the HNO3 solution or the exact amount of HNO3 reacting with NaOH, you will need to use the concept of stoichiometry. The balanced chemical equation for the reaction between HNO3 and NaOH is:
HNO3 + NaOH → NaNO3 + H2O
By knowing the balanced equation and the amount of NaOH used, you can calculate the amount of HNO3 reacted. The molar ratio between HNO3 and NaOH is 1:1, meaning one mole of HNO3 reacts with one mole of NaOH. From there, you can determine the concentration or amount of HNO3 based on the volume of the HNO3 solution used.
Please note that the exact calculations will depend on the specific concentrations and volumes used in your titration experiment.