Em tham khảo nha:
\(\begin{array}{l}
*A{l_2}{O_3}\\
\% {m_{Al}} = \dfrac{{27 \times 2}}{{27 \times 2 + 16 \times 3}} \times 100\% = 52,94\% \\
\% {m_O} = 100 - 52,94 = 47,06\% \\
*Al{(OH)_3}\\
\% {m_{Al}} = \dfrac{{27}}{{27 + (16 + 1) \times 3}} \times 100\% = 34,62\% \\
\% {m_O} = \dfrac{{16 \times 3}}{{27 + (16 + 1) \times 3}} \times 100\% = 61,54\% \\
\% {m_H} = 100 - 34,62 - 61,54 = 3,84\% \\
*KCl\\
\% {m_K} = \dfrac{{39}}{{39 + 35,5}} \times 100\% = 52,35\% \\
\% {m_{Cl}} = 100 - 52,35 = 47,65\%
\end{array}\)
