# $Al_2O_3$ is reduced by electrolysis at low potentials and high currents. If $4.0\times10^{4}$ amperes of current is passed through molten $Al_2O_3$ for 6 hours, what mass of aluminium is produced ? (Assume 100% current efficiency, at. mass of$Al = 27 g mol^{–1}$) -
( A ) $1.3\times10^4$
( B ) $8.1\times10^4$
( C ) $2.4\times10^5$
( D ) $9.0\times10^3$