Respuesta :
Using the Henderson equation , pH = pKₐ + log(salt/acid)
pH-value for given mixture is 4.74
When a strong base like potasium hydroxide (KOH ) reacts with weak acid like acetic acid (CH₃COOH) form a salt ( CH₃COOK ) and water . This type of reaction is called Neutralization reaction.
CH₃COOH (aq) + KOH (aq) ------> CH₃COO⁻K⁺ (aq) + H₂O(aq)
Given that
- Hen25 ml of potasium hydroxide( KOH) will react with 25ml of acetic acid (CH₃COOH) of both 0.200m give potasium acetate ( Ch₃COO⁻K⁺) 25ml of strength 0.200m. The unreaceted acetic acid will be present there.
- Number of moles of KOH = 0.200×25 ×10⁻³
= 5 × 10⁻³mol
- Number of moles of CH₃COO⁻K⁺= 0.200×25×10⁻³ = 5 × 10 ⁻³mol
- Number of moles of CH₃COOH = 5 × 10⁻³ mol
Now , using the Henderson-Hasselbalch equation to find the p-H value
p-H = pKa + log ( salt or conjugate base / weak acid ) ------(1)
where Kₐ is dissociation constant
Since, Kₐ value for acetic acid is 3.8×10⁻⁵
=> pKₐ = 4.74
put the values in (1)
p-H = 4.74 + log ( 5/5) = 4.74 + 0 = 4.74
So, p-H value for solution is 4.74 ..
p-H value of substance or solution refered the nature of solution is acidic or basic .
To learn more about p-H value , refer :
https://brainly.com/question/26424076
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