Câu 1:
(1) \(4FeS_2+11O_2\underrightarrow{t^o}2Fe_2O_3+8SO_2\)
(2) \(Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O\)
(3) \(Fe_2\left(SO_4\right)_3+6NaOH\rightarrow2Fe\left(OH\right)_3\downarrow+3Na_2SO_4\)
(4) \(2Fe\left(OH\right)_3\underrightarrow{t^o}Fe_2O_3+3H_2O\)
Câu 2
a) 2K + 2H2O --> 2KOH + H2
Ba+ 2H2O --> Ba(OH)2 + H2
b)\(n_{H_2}=\dfrac{1,344}{22,4}=0,06\left(mol\right)\)
Gọi số mol K, Ba là a, b
=> 39a + 137b = 7,04
PTHH: 2K + 2H2O --> 2KOH + H2
______a---------------------->0,5a
Ba+ 2H2O --> Ba(OH)2 + H2
b--------------------------->b
=> 0,5a + b = 0,06
=> a = 0,04; b = 0,04
=> \(\left\{{}\begin{matrix}\%K=\dfrac{0,04.39}{7,04}.100\%=22,159\%\\\%Ba=\dfrac{0,04.137}{7,04}.100\%=77,841\%\end{matrix}\right.\)
