Chemistry: The Central Science (13th Edition)

Published by Prentice Hall
ISBN 10: 0321910419
ISBN 13: 978-0-32191-041-7

Chapter 20 - Electrochemistry - Exercises - Page 903: 20.60

Answer

Step 3: Plug answers in the first equation... $$ \begin{aligned} W_{\text {max }} & =-n F E \\ & =-(1.53)(96485)(1.1 \mathrm{~V}) \\ & =-1.62 \times 10^{5} \mathrm{~J} \end{aligned} $$ Step 4: Convert work energy per mole... $$ \begin{aligned} & =\left(-1.62 \times 10^{5} \mathrm{~J}\right) /(0.765 \mathrm{~mol} \text { of } \mathrm{Cu}) \\ & =-212267 \mathrm{~J} / \mathrm{mol} \text { of } \mathrm{Sn}=-212 \mathrm{KJ} / \mathrm{mol} \text { of } \mathrm{Cu} \end{aligned} $$

Work Step by Step

$W_{\text {max }}=-n F E$ $n=$ mol of $e^{-}$ $F=96485$ Step 1: $Z n(s) \rightarrow Z n^{+2}(a q)+2 e^{-} \quad E_{\text {red }}=-0.763 \mathrm{~V}$ $$ \mathrm{Cu}^{+2}(s)+2 e^{-} \rightarrow \mathrm{Cu}(s) \quad E_{\text {red }}=+0.337 \mathrm{~V} $$ $E_{\text {Cell }}=E_{\text {red }}($ cathode $/$ reduced $)-E_{\text {red }}($ Anode/Oxidized $)=0.337 \mathrm{~V}-(-0.763 \mathrm{~V})=1.1 \mathrm{~V}$ Step 2: find $\mathrm{n}$ given that $50.0 \mathrm{~g}$ of $\mathrm{Cu}$ has been consumed. $$ \begin{aligned} & \frac{50 \mathrm{~g}}{65.39 \mathrm{~g} / \mathrm{mol}}=\frac{\text { mass }}{\text { molarmass }}=\text { moles of } \mathrm{Cu}=0.765 \\ & 0.765 \mathrm{~mol} \text { of } \mathrm{Cu} \times \frac{2 \mathrm{~mol} \text { of } \mathrm{e}^{-}}{1 \text { mol of } \mathrm{Cu}}=1.53=n \end{aligned} $$ Step 3: Plug answers in the first equation... $$ \begin{aligned} W_{\text {max }} & =-n F E \\ & =-(1.53)(96485)(1.1 \mathrm{~V}) \\ & =-1.62 \times 10^{5} \mathrm{~J} \end{aligned} $$ Step 4: Convert work energy per mole... $$ \begin{aligned} & =\left(-1.62 \times 10^{5} \mathrm{~J}\right) /(0.765 \mathrm{~mol} \text { of } \mathrm{Cu}) \\ & =-212267 \mathrm{~J} / \mathrm{mol} \text { of } \mathrm{Sn}=-212 \mathrm{KJ} / \mathrm{mol} \text { of } \mathrm{Cu} \end{aligned} $$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.