You visited us 1 times! Enjoying our articles? Unlock Full Access!

Sodium Thiosulphate

A hydrogen el...

Question

A hydrogen electrode placed in a buffer solution of CH $_{3}$ COONa and acetic acid in the ratio's x : y and y : x has reduction electrode potential values E $_{1}$ volt and E $_{2}$ volt respectively at 25 $^{o}$ C. The pK $_{a}$ values of acetic acid is (E $_{1}$ and E $_{2}$ are oxidation potential):

\frac{E_{1} + E_{2}}{0.118}

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

\frac{E_{2} - E_{1}}{0.118}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

- \frac{E_{1} + E_{2}}{0.118}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

- \frac{E_{2} - E_{1}}{0.118}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A $\frac{E_{1} + E_{2}}{0.118}$
$E_{1} = E^{o} - \frac{0.059}{1} l o g [H^{+}]_{1}$

$E_{2} = E^{o} - \frac{0.059}{1} log [H^{+}]_{2}$

On adding (also $E_{H}^{o} = 0$ )

$E_{1} + E_{2} = - \frac{0.059}{1} (log (H^{+})_{1} + log (H^{+})_{2})$

Now for $C H_{3} C O O H ⇌ C H_{3} C O O^{-} + H^{+}$
$[H^{+}] = \frac{K_{a} [C H_{3} C O O H]}{[C H_{3} C O O^{-}]}$
$∴ [H^{+}]_{1} = K_{a} \cdot \frac{y}{x}$
$[H^{+}]_{2} = K_{a} \cdot \frac{x}{y}$
$∴ E_{1} + E_{2} = - \frac{0.059}{1} [l o g \frac{K_{a} . y}{x} + l o g \frac{K_{a} . x}{y}]$
$= - 0.059 [2 l o g K_{a}]$

$l o g K_{a} = \frac{E_{1} + E_{2}}{2 \times (- 0.059)}$

$l o g K_{a} = - \frac{E_{1} + E_{2}}{0.118}$
$p K_{a} = (E_{1} + E_{2}) / 0.118$

Suggest Corrections

Similar questions

A hydrogen electrode placed in a buffer solution of $C H_{3} C O O N a$ and $C H_{3} C O O H$ in the ratios $x : y$ and $y : x$ has electrode potential values $E_{1}$ volts and $E_{2}$ volts respectively at 25 $^{0}$ C . The $p K_{a}$ value of acetic acid is :

[ $E_{1}$ and $E_{2}$ are oxidation potentials]

Q. A hydrogen electrode is placed in a buffer solution of acetic acid and sodium acetate in the ratio

y : x

and

x : y

has electrode potential values

E_{1}

and

E_{2}

volts respectively.

p K_{a}

value for acetic acid is__________.
(

E_{1}

and

E_{2}

are oxidation potentials).

Q. A hydrogen electrode placed in a solution containing sodium acetate and acetic acid in the concentration ratios of

x : y

and

y : x

has electrode potential values

E_{1}

and

E_{2}

volts, respectively, at

25^{\circ} C

. The

p K_{a}

value of acetic acid is:

A hydrogen electrode placed in a buffer solution of $C H_{3} C O O N a$ and $C H_{3} C O O H$ in the molar ratios x : y and y : x has oxidation potentials $E_{1}$ and $E_{2}$ volts respectively at 298 $K, (p_{H_{2}} = 1 a t m)$ . The $p K_{a}$ a value of acetic acid will be given by

Q. A hydrogen electrode placed in a solution containing sodium acetate and acetic acid in the concentration ratios of

x : y

and

y : x

has electrode potential values

E_{1}

and

E_{2}

volts, respectively, at

25^{\circ} C

. The

p K_{a}

value of acetic acid is:

Join BYJU'S Learning Program

A hydrogen electrode placed in a buffer solution of CH3COONa and acetic acid in the ratio's x : y and y : x has reduction electrode potential values E1 volt and E2 volt respectively at 25oC. The pKa values of acetic acid is (E1 and E2 are oxidation potential):