Electrochemistr...

A shiny brown-coloured element 'X' on heating in air becomes black in colour. Name the element 'X'?

Assertion: Rusting of Fe is quicker in saline water than in ordinary water.
Reason: Presence of $$Na^+$$ and $$Cl^-$$ ions increase the conductance of the saline water.

Assertion: The amount of charge carried by one mole electrons is the same as carried by one mole of $$K^{\oplus}$$ ions.
Reason: one mole electrons and one mole $$K^{\oplus}$$ ions carry one faraday charge each.

An electrochemical cell stops working after some time because:

calculate $$\Delta G_{f}^{\ominus}$$ of the reaction :
$$Ag^{\oplus}(aq)\, +\, Cl^{\ominus}(aq)\, \rightarrow\, AgCl(s)$$
Given : $$\Delta G^{\ominus_{AgCl}}\, =\, - 109\, kJ\, mol^{-1}$$
$$\Delta G^{\ominus}_{(Cl^{\ominus})}\, =\, -\, 129\, kJ\, mol^{-1}$$
$$\Delta G^{\ominus}_{(Ag^{\oplus)}}\, =\, -\, 77\, kJ\, mol^{-1}$$

The amount of charge carried by $$M^{3-}$$ ion is:

The electric charge for electrode deposition of 1 g equivalent of a substance is:

The charge carriers in metallic conductors and in electrolytes are respectively:

If $$E^{\ominus}_{Fe^{3+} | Fe}$$ and $$E^{\ominus}_{Fe^{2+} | Fe}$$ are $$-0.36 V$$ and $$-0.439 V$$, respectively, then the value of $$E^{\ominus}_{Fe^{3+} |
Fe^{2+}}$$ is:

Total charge required to convert three moles of $$Mn_3O_4$$ to $$MnO_4^{-}$$ in alkaline medium will be: