The particles are quite tightly packed together but still have enough room to be able to move and flow, their bonds aren't as strong as a solids are
Concentration of the reactant,pressure,surface
area of the reactant and temperatur
It is important for the pH of blood to remain constant because your blood would ionize and burn up if the pH wasn't constant. And if the pH was too high, bacteria ( good and bad, and foreign) would end up dying, as well as yourself.
