There are many types of concentrations in science.
The concentration you are referring to is no. of moles of H+ / total volume (or total mass). However, PH is not determined by this type of concentration.
PH is determined by the no. of moles of H+ ions / total no. of moles of H+ and OH- ions. Suppose you added a certain amount of vegetable oil to the solution, obviously the volume and the mass increase at the same time, but do you think it is logical to deduce the PH value will increase?
Originally posted by frekiwang:There are many types of concentrations in science.
The concentration you are referring to is no. of moles of H+ / total volume (or total mass). However, PH is not determined by this type of concentration.
PH is determined by the no. of moles of H+ ions / total no. of moles of H+ and OH- ions. Suppose you added a certain amount of vegetable oil to the solution, obviously the volume and the mass increase at the same time, but do you think it is logical to deduce the PH value will increase?
Because the vegetable oil and the aqueous solution are immiscible, the volume of the aqueous solution does not change, and therefore pH of each of the two solutions (oil solution and aqueous solution) remain unchanged upon adding them together (since they're immiscible and thus remain in separate layers).