Answer:
pKa of the acid is 3.6
Explanation:
When a weak acid, HX, reacts with NaOH, the conjugate base, X⁻, is produced:
HX + NaOH → X⁻ + Na⁺ + H₂O
At the half neutralized solution, [HX] = [X-]
Based on Henderson-Hasselbalch equation:
pH = pKa + log [ X⁻] / [HX]
<em>Where pH is the pH of the buffer = 3.6</em>
<em>pKa is the pka of the solution</em>
<em>And as [ X⁻] = [HX], [ X⁻] / [HX] = 1</em>
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Replacing:
3.6 = pKa + log 1
3.6 = pKa + 0
<h3>pKa of the acid is 3.6</h3>
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Step 1:
Write down Chemical formula, Overall compound is neutral, so overall charge on it is zero,
Na₃AsO₂ = 0
Step 2:
Write down the oxidation state of known elements, i.e O.S of Na is +1, and O.S of O is -2, Now put these values in above formula.
(+1)₃ + As + (-2)₂ = 0
Step 3:
Now solve for As,
(+1)₃ + As + (-2)₂ = 0
+3 + As - 4 = 0
As = 4 - 3
As = +1
Result:
Oxidation state of Arsenic in Na₃AsO₂ is +1.
Conduction as it transmits energy from solid to solid through a medium