Is 20.0 mL of 1.0M CH3COOH and 10.0mL of 1.0 M NaOH a buffer solution of 3?
It is a buffer but the pH is not 3. Looks more like pH = 4.74 to me but check my arithmetic on that.
To determine whether the given solution is a buffer solution or not, we need to check if the concentrations of both the weak acid (CH3COOH) and the conjugate base (CH3COO-) are within a certain range. Specifically, for a buffer solution, the ratio of the concentrations of the weak acid and its conjugate base should be approximately 1:1.
First, let's calculate the number of moles of CH3COOH and NaOH in the solution:
Moles of CH3COOH = Volume (in L) × Concentration (in mol/L)
= 0.020 L × 1.0 mol/L
= 0.020 mol
Moles of NaOH = Volume (in L) × Concentration (in mol/L)
= 0.010 L × 1.0 mol/L
= 0.010 mol
Next, let's calculate the resulting concentrations of CH3COOH and CH3COO- (formed from the reaction of CH3COOH and NaOH):
Total volume of solution = volume of CH3COOH + volume of NaOH
= 0.020 L + 0.010 L
= 0.030 L
Concentration of CH3COOH = Moles of CH3COOH / Total volume of solution
= 0.020 mol / 0.030 L
= 0.67 M
Concentration of CH3COO- = Moles of NaOH / Total volume of solution
= 0.010 mol / 0.030 L
= 0.33 M
Now, let's check if the concentration ratio is approximately 1:1:
Concentration ratio of CH3COOH to CH3COO- = 0.67 M / 0.33 M
≈ 2:1
Since the concentration ratio is not within the preferred range of approximately 1:1, the given solution is not a buffer solution.
In summary, the given solution of 20.0 mL of 1.0 M CH3COOH and 10.0 mL of 1.0 M NaOH is not a buffer solution of 3.