Titrating ASA Tablets: NaHO and Ethanol

[appykid]

How do I find the quantity of active ingredient in a commercial ASA tablet, using titration and NaHO? I think that I'm supposed to use ethanol too.

 

[chemisttree]

When I did that test back in the day, we used iron to complex with the stuff and measured the intensity of the Fe complex. You could use NaOH in theory but you will need to get the whole tablet to dissolve to accurately analyze it. Ethanol should work but I'm not sure.

We hydrolyzed the acetylsalicyclic acid with excess NaOH to salicylate and then adjusted the pH to neutral and added the Fe to generate the purple complex. I remember using a Spec 20 for the analysis.

 

[ravenprp]

To find the quantity of active ingredient in a commercial ASA tablet using titration and NaHO, you will need to follow a few steps. First, you will need to prepare a standard solution of NaHO by dissolving a known mass of the compound in a known volume of water. This solution will be used to titrate the ASA tablet.

Next, you will need to crush and dissolve the ASA tablet in a known volume of ethanol. This will ensure that the active ingredient is fully dissolved and can be accurately titrated. You can then titrate the ASA solution with the NaHO solution until the endpoint is reached. The endpoint is when the solution turns a light pink color, indicating that all the ASA has reacted with the NaHO.

To calculate the quantity of active ingredient in the ASA tablet, you will need to use the following formula:

Quantity of active ingredient (in grams) = (volume of NaHO solution used in titration x concentration of NaHO solution x molecular weight of ASA) / volume of ethanol used to dissolve the ASA tablet

By using this formula, you can determine the amount of active ingredient present in the ASA tablet. It is important to note that this method may not be 100% accurate, as there may be other ingredients or impurities present in the tablet that can affect the titration results. Therefore, it is always best to confirm your results with other analytical methods.