a) \(M_2\left(CO_3\right)_n+nH_2SO_4\rightarrow M_2\left(SO_4\right)_n+nCO_2+nH_2O\)
b) Giả sử có 100g dd H2SO4 9,8%
\(n_{H_2SO_4}=\dfrac{100.9,8\%}{98}=0,1\left(mol\right)\)
PTHH: M2(CO3)n + nH2SO4 --> M2(SO4)n + nCO2 + nH2O
\(\dfrac{0,1}{n}\)<--------0,1--------->\(\dfrac{0,1}{n}\)--------->0,1
\(m_{dd.sau.pư}=\dfrac{0,1}{n}\left(2.M_M+60n\right)+100-0,1.44=\dfrac{0,1}{n}\left(2.M_M+60n\right)+95,6\left(g\right)\)
\(m_{M_2\left(SO_4\right)_n}=\dfrac{0,1}{n}\left(2.M_M+96n\right)\left(g\right)\)
=> \(C\%_{muối}=\dfrac{\dfrac{0,1}{n}\left(2.M_M+96n\right)}{\dfrac{0,1}{n}\left(2.M_M+60n\right)+95,6}.100\%=14,18\%\)
=> MM = 28n (g/mol)
Xét n = 2 thỏa mãn => MM = 56 (g/mol)
=> M là Fe