a,
\(KMnO_4:\)
\(\%K=\dfrac{39}{158}\times 100\%=24,68\%\\ \%Mn=\dfrac{55}{158}\times 100\%=34,81\%\\ \%O=\dfrac{16\times 4}{158}\times 100\%=40,51\%\)
\(KClO_3:\)
\(\%K=\dfrac{39}{122,5}\times 100\%=31,84\%\\ \%Cl=\dfrac{35,5}{122,5}\times 100\%=28,98\%\\ \%O=\dfrac{16\times 3}{122,5}\times 100\%=39,18\%\)
\(Al_2O_3:\)
\(\%Al=\dfrac{27\times 2}{102}\times 100\%=52,94\%\\ \%O=\dfrac{16\times 3}{102}\times 100\%=47,06\%\)
\(Na_2CO_3:\)
\(\%Na=\dfrac{23\times 2}{106}\times 100\%=43,4\%\\ \%C=\dfrac{12}{106}\times 100\%=11,32\%\\ \%O=\dfrac{16\times 3}{106}\times 100\%=45,28\%\)
\(Fe_2(SO_4)_3:\)
\(\%Fe=\dfrac{56\times 2}{400}\times 100\%=28\%\\ \%S=\dfrac{32\times 3}{400}\times 100\%=24\%\\ \%O=\dfrac{16\times 4\times 3}{400}\times 100\%=48\%\)
b,
\(M_{\text{quặng sắt}}=\dfrac{232}{80\%}=290\ g.\\ \%Fe=\dfrac{56\times 3}{290}=57,93\%\\ \%O=\dfrac{16\times 4}{290}\times 100\%=22,07\%\\ M_{\text{quặng nhôm}}=\dfrac{102}{60\%}=170\ g.\\ \%Al=\dfrac{27\times 2}{170}\times 100\%=31,76\%\\ \%O=\dfrac{16\times 3}{170}\times 100\%=28,24\%\)
chúc bạn học tốt!
