Consider the following cell reaction :
$C{d_{(s)}} + H{g_2}S{O_{4(s)}} + {9 \over 5}{H_2}{O_{(l)}}$ $\rightleftharpoons$ $CdS{O_4}.{9 \over 5}{H_2}{O_{(s)}} + 2H{g_{(l)}}$
The value of $E_{cell}^0$ is 4.315 V at 25$^\circ$C. If $\Delta$H$^\circ$ = $-$825.2 kJ mol$-$1, the standard entropy change $\Delta$S$^\circ$ in J K$-$1 is ___________. (Nearest integer) [Given : Faraday constant = 96487 C mol$-$1]
Answer (integer)
25
Solution
$\Delta G^\circ = - nFE^\circ = \Delta H^\circ - T\Delta S^\circ$<br><br>$\therefore$ $\Delta$S$^\circ$ $= {{\Delta H^\circ + nFE^\circ } \over T}$<br><br>$= {{( - 825.2 \times {{10}^3}) + (2 \times 96487 \times 4.315)} \over {298}}$<br><br>$= {{ - 825.2 \times {{10}^3} + 832.682 \times {{10}^3}} \over {298}}$<br><br>$= {{7.483 \times {{10}^3}} \over {298}} = 25.11$ JK<sup>$-$1</sup> mol<sup>$-$1</sup><br><br>$\therefore$ Nearest integer answer is 25.
About this question
Subject: Chemistry · Chapter: Electrochemistry · Topic: Electrochemical Cells
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