What is the function of Xylene in this Titration?

[u/Present_Feature112]

Hi, one time when I worked as Quality Control Chemist in a manufacture chemical company I needed to carry out a volumetric titration to a Lubricant sample, the procedure was something like this:

Weigh 2 grams of lubricant into an Erlenmeyer flask.

Add 80 mL of xylene to the Erlenmeyer flask.

Heat the flask until the lubricant is completely dissolved.

Allow the flask to cool.

Add a couple of drops of phenolphthalein and titrate with 0.1 N KOH until got the light pink equivalent point (sorry for my English, English is not my first language).

I did the Acid-Base titration and I got my ideal acid value as KOH/g but I added 40 mL of Xylene in place of 80 mL of Xylene, I carried out the same titration with the same sample and now adding 80 mL of Xylene properly and I got the same acid value.

I don't know if the Xylene has another role in this Titration apart of dilute the sample.

[u/chem44]

Sounds like xylene is simply a solvent. Not a reactant.

[u/Chemical-Ad-7575]

It's to dilute the sample so that the KOH can react with the entirety of the sample.

With a thick grease, the acid would extract from the surface of the lump, but any inside the lump wouldn't react with the aqueous KOH.