A buffer solution contains an equivalent amount of acid and base. The pH of the solution with an acid dissociation constant (pKa) value of 3.75 is 3.82.
<h3>What is pH?</h3>
The amount of hydrogen or the proton ion in the solution is expressed by the pH. It is given by the sum of pKa and the log of the concentration of acid and bases.
Given,
Concentration of salt [HCOO⁻] = 0.24 M
Concentration of acid [HCOOH] = 0.20 M
The acid dissociation constant (pKa) = 3.75
pH is calculated from the Hendersons equation as,
pH = pKa + log [salt] ÷ [acid]
pH = 3.75 + log [0.24] ÷ [0.20]
= 3.75 + log (1.2)
= 3.75 + 0.079
= 3.82
Therefore, 3.82 is the pH of the buffer.
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There are 4 atoms presented in BH3
Answer:
0.387 g
Explanation:
pH of the buffer = 1
V = Volume of solution = 100 mL
[HA] = Molarity of HA = 0.1 M
= Acid dissociation constant =
(assuming base as
)
Molar mass of base = 322.2 g/mol
pKa is given by

From the Henderson-Hasselbalch equation we get
![pH=pK_a+\log\dfrac{[A^-]}{[HA]}\\\Rightarrow pH-pK_a=\log\dfrac{[A^-]}{[HA]}\\\Rightarrow 10^{pH-pK_a}=\dfrac{[A^-]}{[HA]}\\\Rightarrow [A^-]=10^{pH-pK_a}[HA]\\\Rightarrow [A^-]=10^{1-1.92}\times0.1\\\Rightarrow [A^-]=0.01202\ \text{M}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%5Cdfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D%5C%5C%5CRightarrow%20pH-pK_a%3D%5Clog%5Cdfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D%5C%5C%5CRightarrow%2010%5E%7BpH-pK_a%7D%3D%5Cdfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D%5C%5C%5CRightarrow%20%5BA%5E-%5D%3D10%5E%7BpH-pK_a%7D%5BHA%5D%5C%5C%5CRightarrow%20%5BA%5E-%5D%3D10%5E%7B1-1.92%7D%5Ctimes0.1%5C%5C%5CRightarrow%20%5BA%5E-%5D%3D0.01202%5C%20%5Ctext%7BM%7D)
Moles of base

Mass of base is given by

The required mass of the base is 0.387 g.