1 \(1.03 \times {10^{18}}\)
2 \(3.01 \times {10^{18}}\)
3 \(4.95 \times {10^{26}}\)
4 \(7.31 \times {10^{20}}\)
Explanation:
\[\begin{array}{l}
{\rm{A}}{{\rm{l}}^{{\rm{3 + }}}} + {\rm{3}}{{\rm{e}}^ - } \to {\rm{Al}}\\
27{\rm{g}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,27{\rm{g}}
\end{array}\]
27 g of Al is reduced by \(3 \times 6.023 \times {10^{23}}\)
\(\therefore \,4.5 \times {10^{ - 5}}{\rm{g}}\,\) of Al will be reduced by \( = \frac{{3 \times 6.023 \times {{10}^{23}} \times 4.5 \times {{10}^{ - 5}}}}{{27}}\)
\({\rm{ = }}\,{\rm{3}}{\rm{.01 \times 1}}{{\rm{0}}^{{\rm{18}}}}{\rm{electrons}}\)