$5$A$.$ A pharmaceutical drug A was quantified by pulse voltammetry; it had an $E_{\frac{1}{2}}$ value$5$A$.$ A pharmaceutical drug A was quantified by pulse voltammetry; it had an $E_{\frac{1}{2}}$ value

of $-0\mathrm{.}265V($vs$.$ SCE$)$ in $0\mathrm{.}5M{H}_{2}S{O}_4.$ A $50\mathrm{.}0-mL$ sample containing A gave a wave

amplitude of $0\mathrm{.}37A.$ When $2\mathrm{.}00mL$ of $3\mathrm{.}00mM$ in $0\mathrm{.}5M{H}_{2}S{O}_4$ were added to the

sample, the wave amplitude increased to $0\mathrm{.}80A.$

Compute the molarity of $A$ in the unknown.

Nezhadali and Sharifi $($Engineering$,2010,2,1026-1030)$ have reported complex

formation data on four different cations, $M^{2+}(M=Ni,Cu,Zn,Pb)$ with $o-$

phenylenediamine as ligand in DMF$/$water mixtures containing $KN{O}_3$ as supporting

electrolyte. The figure below $($Figure $1)$ presents SWP data for the $Z{n}^{2+}$ case using a

HMDE; curves are shown both in the absence and presence of the ligand.

$n=2$

Figure $1.$ The square wave polarograms of $0\mathrm{.}1mMZ{n}^{2+}$ ion

in a $DM\frac{F}{H_2}O(60\%DMF+40\%H_{2}O)$ binary system with

different concentration of $0-$PDA ligand: $(1)0,(2)0\mathrm{.}19,(3)$

$0\mathrm{.}25,(4)0\mathrm{.}3,(5)0\mathrm{.}35$ and $(6)0\mathrm{.}39mM.$

$($The $\text{'}n\text{'}$ in ordinate above stands for nano and $\text{'}m\text{'}$ in the abscissa stands for milli.$)$

$($i$)$

$($i$)$ Use the grid to work up these data as needed, to compute: $($a$)$ The combining ratio of

complexing agent to cation, $p$; and $($b$)$ The complex formation constant, $K_f.$ Show all

subsequent calculations neatly and clearly.

$($ii$)$ Judging from the data trends in Figure $1,$ what can you conclude about the relative

thermodynamic stability of the complex vs$.$ the un$-$complexed metal ions? Support

you answer with a sentence of rationalization.

of $-0\mathrm{.}265V($vs$.$ SCE$)$ in $0\mathrm{.}5M{H}_{2}S{O}_4.$ A $50\mathrm{.}0-mL$ sample containing A gave a wave

amplitude of $0\mathrm{.}37A.$ When $2\mathrm{.}00mL$ of $3\mathrm{.}00$mMA in $0\mathrm{.}5M{H}_{2}S{O}_4$ were added to the

sample, the wave amplitude increased to $0\mathrm{.}80A.$

$5$B$.$ Compute the molarity of $A$ in the unknown.

Nezhadali and Sharifi $($Engineering$,2010,2,1026-1030)$ have reported complex

formation data on four different cations, $M^{2+},(M=Ni,Cu,Zn,Pb)$ with $o-$

phenylenediamine as ligand in DMF$/$water mixtures containing $KN{O}_3$ as supporting

electrolyte. The figure below $($Figure $1)$ presents SWP data for the $Z{n}^{2+}$ case using a

HMDE; curves are shown both in the absence and presence of the ligand.

$n=2$

Figure $1.$ The square wave polarograms of $0\mathrm{.}1mMZ{n}^{2+}$ ion

in a $DM\frac{F}{H_2}O(60\%DMF+40\%H_{2}O)$ binary system with

different concentration of $0-$PDA ligand: $(1)0,(2)0\mathrm{.}19,(3)$

${0\mathrm{.}25}_{?}(4)0\mathrm{.}3,(5)0\mathrm{.}35$ and $(6)0\mathrm{.}39mM$

$($The $\text{'}n\text{'}$ in ordinate above stands for nano and $\text{'}m\text{'}$ in the abscissa stands for milli.$)$

$($i$)$ Use the grid to work up these data as needed, to compute: $($a$)$ The combining ratio of

complexing agent to cation, $p$; and $($b$)$ The complex formation constant, $K_f.$ Show all

subsequent calculations neatly and clearly.

$($ii$)$ Judging from the data trends in Figure $1,$ what can you conclude about the relative

thermodynamic stability of the complex vs$.$ the un$-$complexed metal ions? Support

yout answer with a sentence of rationalization.

$($iii$)$ I read from the above paper under the Experimental Section that the SWP frequency

was $50Hz$ and the potential scan rate was $250m\frac{V}{s}.$ What would have been the staircase

shift used in these experiments?

$[$ Answer all questions together, It is a full question$]$