the value of pkw at 25c is
answer is 14
To determine the value of pkw at 25c, we need to understand what "pkw" represents. pkw is the symbol for the ionization constant of water, also known as the equilibrium constant for the self-ionization of water.
The ionization constant of water, Kw, is a measure of the extent to which water molecules dissociate into hydrogen ions (H+) and hydroxide ions (OH-) in an aqueous solution. It is defined as the product of the concentrations of these ions in water:
Kw = [H+][OH-]
To calculate the value of pkw at 25c, we need to know the concentration of H+ (hydrogen ions) and OH- (hydroxide ions) at that temperature.
At 25°C (room temperature), the concentration of H+ and OH- ions in pure water is equal and can be considered as 1.0 x 10^-7 mol/L.
Using the equilibrium constant expression, we can calculate the value of Kw at 25°C:
Kw = [H+][OH-] = (1.0 x 10^-7) * (1.0 x 10^-7) = 1.0 x 10^-14
Now, to find the value of pkw, we take the negative logarithm (base 10) of the Kw value:
pkw = -log10(Kw) = -log10(1.0 x 10^-14)
Calculating this logarithm, we get:
pkw ≈ 14
Therefore, the value of pkw at 25°C is approximately 14.