At what concentration of ZnSO₄,  the reduction  potential  of Zn electrode is –0.82 V (SRP of Zn electrode is  
(–0.76 V)

$\begin{array}{l}Z{n}^{2+}+2e^{-}\to Zn\\ E_{RP}=E_{RP}-\frac{0.0591}{2}\log \frac{1}{\left[Z{n}^{2+}\right]}\\ E_{RP}=-0.76-\frac{0.0591}{2}\log \frac{1}{\left[Z{n}^{2+}\right]}\\ -0.82=-0.76-\frac{0.06}{2}\log \frac{1}{\left[Z{n}^{2+}\right]}\\ -0.06=\frac{-0.06}{2}\log \frac{1}{\left[Z{n}^{2+}\right]}\\ 2=\log \frac{1}{\left[Z{n}^{2+}\right]}\\ \frac{1}{\left[Z{n}^{2+}\right]}={10}^2\\ \left[Z{n}^{2+}\right]=\frac{1}{100}=0.01M\end{array}$

So, concentration of ZnSO₄ – 0.01 M