Calculate the ratio: [πΆπ»3πΆπππ»] / [πΆπ»3πΆππππ]
That will give a solution with pH of 5.00, given πΎπ = 1.8 Γ 10β5 .
The Henderson-Hasselbalch equation is
pH = pKa + log (base/acid)
pH is 5.00
Convert Ka to pKa. That will be close to 4.75 but you need to do that yourself/
Solve for base/acid concentrations. Base is CH3COONa and acid is CH3COOH
Post your work if you get stuck.
To calculate the ratio [πΆπ»3πΆπππ»] / [πΆπ»3πΆππππ] and determine the solution's pH, we need to use the principles of acid-base equilibrium. Specifically, we will be using the Henderson-Hasselbalch equation.
The Henderson-Hasselbalch equation is as follows:
pH = pKa + log ([A-] / [HA])
Where:
- pH is the measure of acidity or alkalinity of a solution.
- pKa is the logarithmic value of the acid dissociation constant (Ka) of the weak acid.
- [A-] is the concentration of the conjugate base.
- [HA] is the concentration of the weak acid.
In this case, we have the weak acid CH3COOH (acetic acid) and its conjugate base CH3COONa (sodium acetate).
Given:
- Ka = 1.8 Γ 10^-5
We know that pKa = -log(Ka). So we can calculate the pKa value using the given Ka:
pKa = -log(1.8 Γ 10^-5)
Next, we'll plug the values into the Henderson-Hasselbalch equation:
pH = pKa + log ([A-] / [HA])
Since the ratio [CH3COOH] / [CH3COONa] is provided, we can assume that [A-] is equal to [CH3COONa] and [HA] is equal to [CH3COOH]. So the equation becomes:
pH = pKa + log ([CH3COONa] / [CH3COOH])
Now, we can substitute the given values.
pH = pKa + log ([CH3COONa] / [CH3COOH])
pH = (-log(1.8 Γ 10^-5)) + log ([CH3COONa] / [CH3COOH])
pH = (-log(1.8 Γ 10^-5)) + log ([CH3COONa] / [CH3COOH])
Finally, we can calculate the value of pH using a calculator and the given ratio [CH3COOH] / [CH3COONa].