Like a equilibrium constants, the values of Kw depends on temperature. At body temperature (37 C), Kw= 2.4 x 10^-14.
What are the [H3O+] and pH of pure water at body temperature?
sqrt(2.4E-14)= 1.55E-7
which is the (H3O+) concentration
pH=-log above=6.84
To determine the [H3O+] and pH of pure water at body temperature (37°C), we can use the autoionization equation of water:
H2O ⇌ H3O+ + OH-
According to the equation, the concentration of H3O+ (or [H3O+]) is equal to the concentration of OH- (or [OH-]). Since pure water is neutral, the concentration of H3O+ will be equal to that of OH-, and both will be x. Therefore:
[H3O+] = [OH-] = x
We also know that the product of the concentrations of H3O+ and OH- ions is equal to the ionization constant for water (Kw), which is 2.4 x 10^-14 at 37°C:
[H3O+] x [OH-] = Kw
x² = Kw
x² = 2.4 x 10^-14
Taking the square root of both sides, we find:
x ≈ √(2.4 x 10^-14)
x ≈ 1.55 x 10^-7
So, [H3O+] ≈ [OH-] ≈ 1.55 x 10^-7 M
To find the pH, we can use the equation:
pH = -log[H3O+]
pH ≈ -log(1.55 x 10^-7)
pH ≈ 6.81
Therefore, at body temperature (37°C), the [H3O+] and pH of pure water are approximately 1.55 x 10^-7 M and 6.81, respectively.
To find the [H3O+] (concentration of hydronium ions) and pH of pure water at body temperature, we need to use the value of Kw (the ion product of water). Since Kw depends on temperature, we have the value of Kw at body temperature, which is 2.4 x 10^-14.
The equilibrium constant (Kw) for the reaction of water dissociating into hydronium (H3O+) and hydroxide (OH-) ions is given by the equation:
Kw = [H3O+][OH-]
Since we are dealing with pure water, the concentration of [H3O+] is equal to the concentration of [OH-]. Therefore, we can assign a variable 'x' to both concentrations.
For pure water, [H3O+] = [OH-] = x
Substituting this into the equation for Kw, we get:
Kw = x * x
or
2.4 x 10^-14 = x^2
To solve for the concentration of hydronium ions ([H3O+]), we can take the square root of both sides:
√(2.4 x 10^-14) = √(x^2)
1.5 x 10^-7 = x
So, at body temperature, the concentration of hydronium ions ([H3O+]) in pure water is 1.5 x 10^-7 M.
To find the pH of a solution, we can use the equation:
pH = -log[H3O+]
Substituting the value of [H3O+], we get:
pH = -log(1.5 x 10^-7)
pH ≈ 6.82
Therefore, at body temperature, the [H3O+] of pure water is 1.5 x 10^-7 M, and the pH of pure water is approximately 6.82.