Em tham khảo nha:
\(\begin{array}{l}
*Fe{(N{O_3})_3}\\
\% {m_{Fe}} = \dfrac{{56}}{{56 + (14 + 16 \times 3) \times 3}} \times 100\% = 23,14\% \\
\% {m_N} = \dfrac{{14 \times 3}}{{56 + (14 + 16 \times 3) \times 3}} \times 100\% = 17,36\% \\
\% {m_O} = 100 - 23,14 - 17,36 = 59,5\% \\
*CaC{O_3}\\
\% {m_{Ca}} = \dfrac{{40}}{{40 + 12 + 16 \times 3}} \times 100\% = 40\% \\
\% {m_C} = \dfrac{{12}}{{40 + 12 + 16 \times 3}} \times 100\% = 12\% \\
\% {m_O} = 100 - 40 - 12 = 48\% \\
*NaN{O_3}\\
\% {m_{Na}} = \dfrac{{23}}{{23 + 14 + 16 \times 3}} \times 100\% = 27,06\% \\
\% {m_N} = \dfrac{{14}}{{23 + 14 + 16 \times 3}} \times 100\% = 16,47\% \\
\% {m_O} = 100 - 27,06 - 16,47 = 56,47\%
\end{array}\)
