If we suppose that Kw = 1.0x10^-14 at 25C, would it be larger or smaller at 100C? What is the value of K for the reaction 8H + 8OH = 8H2O at 25C? Would this value be smaller, or larger, at 100C?
Wouldn't you expect the ionization of water to increase with increase in temperature. I think I would. So Kw would be larger at 100 C.
Second part:
Remember that if
A + B ==> C and K = (A)(B)/(C), then
2A + 2B ==> 2C and K' = (A)^2(B)^2/(C)^2 = K'^2
To determine whether Kw (the equilibrium constant for the self-ionization of water) would be larger or smaller at 100°C compared to 25°C, we need to consider the effect of temperature on the equilibrium constant.
The equilibrium constant is generally temperature-dependent. According to the Arrhenius equation, as the temperature increases, the value of Kw also increases. This is due to the fact that the forward and reverse reactions at equilibrium are influenced by the change in temperature.
To be more precise, the equilibrium constant can be calculated using the formula:
Kw = [H+][OH-]
Where [H+] represents the concentration of hydronium ions and [OH-] represents the concentration of hydroxide ions.
Since the concentration of hydronium ions and hydroxide ions vary with temperature, the value of Kw changes as well.
Now, let's look at the value of Kw at 25°C which is given as 1.0×10^-14.
To determine the value of K for the reaction 8H + 8OH = 8H2O at 25°C, we can utilize the relationship between the equilibrium constant of the self-ionization of water and the equilibrium constant of the reaction.
The balanced chemical equation shows that 8 hydronium ions (H+) react with 8 hydroxide ions (OH-) to form 8 water molecules (H2O). Therefore, the equation can be rewritten as:
K = [H2O]^8 / ([H+]^8 * [OH-]^8)
Given that Kw = [H+] * [OH-] = 1.0×10^-14, we can substitute this value into the equation:
K = [H2O]^8 / (1.0×10^-14)^8
Since [H2O] is the concentration of water, and water is the solvent, the concentration of water remains constant, and therefore [H2O]^8 can be treated as a constant value.
Now, to answer the second part of the question - would this value be smaller or larger at 100°C?
As mentioned earlier, the equilibrium constant is temperature-dependent. Based on the Arrhenius equation, an increase in temperature will result in a larger equilibrium constant. Therefore, the value of K for the reaction 8H + 8OH = 8H2O would be larger at 100°C compared to 25°C.