So, the concentration of our hydrogen ion, this is equal to the product of the concentration of the H plus ion and the a divided by the concentration of ha. So, the H plus appears on both sides. And so, we can cancel that out. And then, if we bring this side to the left, this denominator to the left side, we get the following equality. So, we see that when the PH is equal to the PKA, when the PH of our solution inside the cell is equal to 9.7. So, somewhere about here, we see that the concentration of the ha is equal to the concentration of the a.