How do I calculate the pH of slime and its effect on viscosity?

[irumi]

TL;DR Summary

So I'm basically doing an experiment where I am going to add different amounts of acid and base in order to change the pH of slime. ( I heard putting acid and base causes the forming and breaking of bonds inside the slime)

How would I be able to calculate the pH of slime?

I learned how to "add" pH's, like I know how to get a new pH from adding one solution to another.
But I'm not sure on how to calculate the pH of slime.
From what i know so far, this is all I will be making to make the slime:
(Poly – Vinyl Alcohol (PVA), water, Tetraborate Na2B4O7 , and deonized water)
Do I need to figure out how much the molarity and amount of all these substances I'm going to use and calculate the pH??

I'm trying to experiment the viscosity of the slime as I put different concentrations of acid and base in the slime.
The ultimate goal I'm trying to get is to see the relationship between pH and viscosity.
(I will be putting slime inside a graduated cylinder, drop a ball inside it, and use the viscosity equation (viscosity = [2(ps-pl)ga2]/9v))++also will I be able to increase the pH of the slime by simply just adding more of the same pH of base? or would I have to change the pH of base every time.

 

[Borek]

Do I need to figure out how much the molarity and amount of all these substances I'm going to use and calculate the pH??

Yes.

pH calculation is a rather broad subject (or, actually, quite a narrow one, depends on how you look at it ;) ).

I suggest you look at any GenChem101 course, they always have part called "chemical equilibria", typically combined with dissociation of acids and bases and pH related stuff, that's what you will need.

Broadly speaking for research like yours calculation of pH is a very good starting point when designing the experiment and estimating amounts of strong acid/base required to change pH, but during the experiment you should simply measure the pH.

Borax solutions, with multiple dissociation steps, are quite challenging to deal with when doing pH calculations by hand, I suggest you look for some specialized software.

 

[irumi]

So basically I designed an experiment to see if adding a base/acid to a slime to change its pH will effect viscosity.
But as I started researching more, I also found out adding borax to slime disturbs the hydrogen bonds of polymers within the slime, just like changing the pH of slime.

Obviously, I don't want to do the same experiment; if adding acid/base is the same thing as changing the borax when making slime, that would be doing basically the same thing.

So i was wondering, is the same thing happening because of the same reason? if so, would there be a way to tweak the experiment a little bit to still see the relationship between pH and viscosity?
When I was reading chemistry behind adding borax to slime, I don't think I saw a lot of pH stuff, so I want to make sure if they are the same thing or not.