Now, at room temperature, this cave value is measured to be 1.8 times ten to negative 16. And the concentration of water in pure water is always a constant value. It's always equal to 55.5. And so because this is a constant and this is a constant, we can plug those values into this equation and we get 1.8 times ten to negative 16 is equal to this multiplied by this, our two unknowns divided by a constant. So 55.5. And so if we bring this to the left side, we multiply them out, we get 1.0 times ten to negative 14 is equal to the product of the concentration of the hydrogen ion and the concentration of that hydroxide ion.