Saturated solution of $KNO_3$ is used to make salt bridge because

Which of the following species acts as a reducing agent during the working of a hydrogen-oxygen fuel cell?

In which cell is the free energy of a chemical reaction directly converted into electricity?

Consider the figure and answer the questions $(i)$ to $(vi)$ given below.
$(i)$ Redraw the diagram to show the direction of electron flow.
$(ii)$ Is the silver plate the anode or cathode?
$(iii)$ What will happen if the salt bridge is removed?
$(iv)$ When will the cell stop functioning?
$(v)$ How will the concentration of $Zn^{2+}$ ions and $Ag^{+}$ ions be affected when the cell functions?
$(vi)$ How will the concentration of $Zn^{2+}$ ions and $Ag^{+}$ ions be affected after the cell becomes 'dead'?

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 .......... $kJ.$
$(F = 96500 \ C \ mol^{-1})$

Standard electrode potentials for a few half cells are mentioned below:
$E^0_{Cu^{2+}/Cu} = 0.34 \ V, E^0_{Zn^{2+}/Zn} = -0.76 \ V$
$E^0_{Ag^{+}/Ag} = 0.80 \ V, E^0_{Mg^{2+}/Mg} = -2.37 \ V$
Which one of the following cells gives the most negative value of $\Delta G^0$?