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![](https://rs.olm.vn/images/avt/0.png?1311)
Ta có: MAl2O3 = 27.2+16.3 = 102 g/mol
%Al = 27.210227.2102.100% = 52,94%
%O = 16.310216.3102.100% = 47,06%
![](https://rs.olm.vn/images/avt/0.png?1311)
a) Theo định luật bào toàn khối lượng , ta có :
mAl2O3 = mAl + mO2
b) Ta có :
mAl2O3 = 54 + 48 = 102 (g)
c) %mAl2O3 = \(\frac{102.100}{150}\%=68\%\)
a)
- PTHH: \(Al_2O_3\rightarrow Al+O_2\)
- Công thức về khối lượng: \(m_{Al_2O_3}=m_{Al}+m_{O_2}\)
b)
\(m_{Al_2O_3}=m_{Al}+m_{O_2}\)
hay \(m_{Al_2O_3}=54+48\)
\(\Rightarrow m_{Al_2O_3}=102\left(g\right)\)
c)
Phần trăm: \(m_{Al_2O_3}\) = \(m_{Al_2O_3}\) / m quặng boxit
\(\frac{150}{102}.100\%=1,5\%\)
câu c mk cũng hk chắc nha bạn!!!!!!!!!
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\left\{{}\begin{matrix}\%Al=\dfrac{27.2}{342}.100\%=15,79\%\\\%S=\dfrac{32.3}{342}.100\%=28,07\%\\\%O=\dfrac{16.12}{342}.100\%=56,14\end{matrix}\right.\)
\(\left\{{}\begin{matrix}\%Fe=\dfrac{56.3}{232}.100\%=72,414\%\\\%O=\dfrac{4.16}{232}.100\%=27,586\%\end{matrix}\right.\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(PTK_X=102\left(đvC\right)\\ \Rightarrow M_X=102\left(\dfrac{g}{mol}\right)\)
\(\Rightarrow m_O=\%O.M_X=47,06\%.102=48\left(g\right)\)
\(\Rightarrow n_O=\dfrac{m}{M}=\dfrac{48}{16}=3\left(mol\right)\)
\(\Rightarrow CTHH.của.M.có.dạng:X_2O_3\)
\(\Leftrightarrow X.2+16.3=102\\ \Leftrightarrow X=27\left(đvC\right)\)
\(\Rightarrow X.là.Al\left(nhôm\right)\)
\(\Rightarrow CTHH.của.M:Al_2O_3\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Bài 1:
\(1,M_{MgCO_3}=84(g/mol)\\ \begin{cases} \%_{Mg}=\dfrac{24}{84}.100\%=28,57\%\\ \%_{C}=\dfrac{12}{84}.100\%=14,29\%\\ \%_{O}=100\%-28,57\%-14,29\%=57,14\% \end{cases}\)
\(2,M_{Al(OH)_3}=78(g/mol)\\ \begin{cases} \%_{Al}=\dfrac{27}{78}.100\%=31,62\%\\ \%_{H}=\dfrac{3}{78}.100\%=3,85\%\\ \%_{O}=100\%-31,62\%-3,85\%=64,53\% \end{cases}\)
\(3,M_{(NH_4)_2HPO_4}=132(g/mol)\\ \begin{cases} \%_{N}=\dfrac{28}{132}.100\%=21,21\%\\ \%_{H}=\dfrac{9}{132}.100\%=6,82\%\\ \%_{P}=\dfrac{31}{132}.100\%=23,48\%\\ \%_{O}=100\%-23,48\%-6,82\%-21,21\%48,49\% \end{cases}\)
\(4,M_{C_2H_5COOCH_3}=88(g/mol)\\ \begin{cases} \%_{C}=\dfrac{48}{88}.100\%=54,55\%\\ \%_{H}=\dfrac{8}{88}.100\%=9,09\%\\ \%_{O}=100\%-9,09\%-54,55\%=36,36\% \end{cases}\)
Bài 2:
\(c,\%_{Al(AlCl_3)}=\dfrac{27}{27+35,5.3}.100\%=20,22\%\\ \%_{Al(Al_2O_3)}=\dfrac{27.2}{27.2+16.3}.100\%=52,94\%\\ \%_{Al(AlBr_3)}=\dfrac{27}{27+80.3}.100\%=10,11\%\\ \%_{Al(Al_2S_3)}=\dfrac{27.2}{27.2+32.3}.100\%=36\%\)
Vậy \(Al_2O_3\) có \(\%Al\) cao nhất và \(AlBr_3\) có \(\%Al\) nhỏ nhất
27,54%
\(M_{Al_2O_3}=27.2+16.3=102\left(DvC\right)\\ \%Al=\dfrac{27.2}{102}.100\%=52,94\%\)
hmm k có đáp án nào hết