The standard Gibbs energy for the given cell reaction in kJ mol^–1 at 298 K is :

Zn(s) + Cu²⁺ (aq) $$ \to $$ Zn²⁺ (aq) + Cu (s),

E° = 2 V at 298 K

(Faraday's constant, F = 96000 C mol^–1)

Calculate the standard cell potential in (V) of the cell in which following reaction takes place :

Fe²⁺(aq) + Ag⁺(aq) $$ \to $$ Fe³⁺(aq) + Ag (s)

Given that

$$E_{A{g^ + }/Ag}^o = xV$$

$$E_{Fe^{2+ }/Fe}^o = yV$$

$$E_{Fe^{3+ }/Fe}^o = zV$$

Given that $${E^\Theta }_{{O_2}/{H_2}O} = 1.23\,V$$ ;

$${E^\Theta }_{{S_2}O_8^{2 - }/SO_4^{2 - }} = 2.05\,V$$

$${E^\Theta }_{B{r_2}/B{r^ - }} = 1.09\,V$$

$${E^\Theta }_{A{u^{3 + }}/Au} = 1.4\,V$$

The strongest oxidizing agent is :

$$ \wedge _m^ \circ $$ for NaCl, HCl and NaA are 126.4, 425.9 and 100.5 S cm² mol^–1, respectively. If the conductivity of 0.001 M HA is-

5 $$ \times $$ 10^–5 S cm^–1, degree of dissociation of HA is -