Sodium propionate, NaC3H7O2, is used as a food preservative. What is the Kb of C3H7O2- given Ka HC3H7O2 = 3.4x10-5.
Well, let me break it down for you in my own clownish way!
We know the Ka value of HC3H7O2, which tells us about its acidity. But in order to find the Kb value, we need to look at the basicity of C3H7O2-.
Now, if you recall your chemistry lessons, you'll remember that the sum of the Ka and Kb values for a conjugate acid-base pair is always equal to 1.
So, if the Ka of HC3H7O2 is 3.4x10-5, then the Kb of C3H7O2- can be found by subtracting Ka from 1.
In this case, the math goes something like this:
1 - 3.4x10-5 = 0.999966
So, with some quick calculations, we find that the Kb of C3H7O2- is approximately 0.999966. However, I must remind you that my calculations are as reliable as a banana peel on a tightrope!
To find the Kb of C3H7O2-, we need to use the relationship between Ka and Kb for a conjugate acid-base pair. The relationship is given by the equation:
Ka × Kb = Kw
Here, Kw is the equilibrium constant for the self-ionization of water, which is equal to 1.0 × 10^(-14) at 25°C.
From the given information, we know the Ka HC3H7O2 = 3.4 × 10^(-5). To find the Kb of C3H7O2-, we rearrange the equation:
Kb = Kw / Ka
Substituting the known values:
Kb = (1.0 × 10^(-14)) / (3.4 × 10^(-5))
Calculating this expression gives us:
Kb ≈ 2.94 × 10^(-10)
Therefore, the Kb of C3H7O2- is approximately 2.94 × 10^(-10).
To find the Kb (base dissociation constant) of C3H7O2-, we can use the relationship between the acidity constant (Ka) and the base dissociation constant (Kb) of a conjugate acid-base pair.
The given Ka value is for the acid HC3H7O2, which can be written as HC3H7O2 ⇌ H+ + C3H7O2-. The conjugate base of HC3H7O2 is C3H7O2-, which can accept a proton (H+) to form HC3H7O2.
The relationship between Ka and Kb is given by the equation: Ka x Kb = Kw, where Kw is the ionization constant of water, which is 1.0 x 10^-14 at 25°C.
To find the Kb of C3H7O2-, we need to rearrange the equation to solve for Kb:
Kb = Kw / Ka
Plugging in the given values, we have:
Kb = (1.0 x 10^-14) / (3.4 x 10^-5)
Calculating this expression, we find:
Kb ≈ 2.94 x 10^-10
Therefore, the Kb value of C3H7O2- is approximately 2.94 x 10^-10.