Hello, Ask Q,
I'm not sure how the term "if dilution and volume will increase" should be interpreted. I'll assume that the question is asking "If a sample is diluted, predict whether both volume and pH will increase or decrease." I will assume we are diluting a strong acid or base.
We can look at the definition of pH for an answer. pH is the negative log of the hydrogen ion concentration: -log[H+].
Concentation will be dependent on any addition of solvent. Adding solvent (dilution) will increase the volume and therefore lower the concentration of [H+]. This will raise the pH. That is slightly counterintuitive, in that reducing concentration raises pH, but it simply reflects that the -log of a decreasing number actually produces a larger result. So if a sample is diluted, iboth it's volume and pH will increase.
The word "diluted" infers a reduction, which it is, but the impact on both pH and volume is an increase.
Bob
