Which of the following is used to avoid leakage of electrolyte in a dry cell?

Which solution is filled in a salt bridge?

In $H_2-O_2$ fuel cell,the reaction occurring at the cathode is:

Given that $\frac{1}{3} \lambda_m^\infty (Fe^{3+}) = 68 \ \Omega^{-1} \ cm^{2} \ eq^{-1}$ and $\frac{1}{2} \lambda_m^\infty (SO_4^{2-}) = 80 \ \Omega^{-1} \ cm^{2} \ eq^{-1}$. What will be the value of $\lambda_{eq}^\infty (Fe_2(SO_4)_3)$? ............ $\Omega^{-1} \ cm^2 \ eq^{-1}$

For the reduction of silver ions with copper metal,the standard cell potential was found to be $+ 0.46 \ V$ at $25^oC.$ The value of standard Gibb's energy,$\Delta G^o$ will be .......... $kJ.$
$(F = 96500 \ C \ mol^{-1})$

The unfavourable electrochemical reaction among the following is