How does the pH of substances change when it goes through soil?

I did a lab in bio where we had to put substances (i.e. water, vinegar, oil) through soil



We would take the pH of the substance before and after it went through the soil



My results were:



Water - before - 7 after - 7

Oil - before - 6 after - 4

Ammonia - before - 12 after - 10

Vinegar - before - 2 after - 3



Does anyone know how the pH changes after penetrating through the soil?How does the pH of substances change when it goes through soil?
The answer to that question depends much on the soil and its pH. If chemicals in the soil react with the substance. First the 'substance' is not the same substance. Second, the pH of the soil needs to be measured before the 'substance' is added.

Water passing through the soil and remaining neutral would indicate no water soluble ions are present in the soil.. Other chemicals are in the soil, some which are acid soluble (as ph rises when vinegar is added). Some oil soluble as pH of oil changes and some soluble in bases.

Now, you do the rest.How does the pH of substances change when it goes through soil?
Most soils have some degree of cation exchange capacity. That is, they loosely hold some cations that were in the soil solution, and they readily exchange those cations with those in the solutions you ran through the soil. (Cations, as you know, are positively charged ions.)



The soil's cation exchange capacity (CEC) gives the soil the ability to buffer the solution you pour through it. With vinegar, the soil removed some H+ ions from your solution and exchanged them for other ions. With the ammonium, the soil removed some of the ammonium ions from solution (NH4+).