Which statement about the Leclanche dry cell is incorrect?

AThe zinc container acts as the anode
BA graphite rod surrounded by a paste of $MnO X_{2}$ and carbon acts as the cathode
CThe electrolyte is a moist paste of $NH X_{4} Cl$ and $ZnCl X_{2}$
DThe cell can be recharged by passing current in the reverse direction

Answer: D

Anode:

Zn Zn X^{2 +} + 2 e X^{-}

; cathode:

MnO X_{2} + NH X_{4} X^{+} + e X^{-} MnO (OH) + NH X_{3}

; the electrolyte is the

NH X_{4} Cl

ZnCl X_{2}

paste, so (A), (B) and (C) are correct. The dry cell is a primary cell: the ammonia formed is taken up as

[Zn (NH X_{3}) X_{2}] X^{2 +}

and the reactions are not reversible, so it cannot be recharged. Statement (D) is incorrect.