Gọi \(n_{FeSO_4.7H_2O}=xmol\)
\(\Rightarrow\left\{{}\begin{matrix}m_{FeSO_4KT}=152x\left(g\right)\\m_{H_2OKT}=126x\left(g\right)\end{matrix}\right.\)
* Trong dd FeSO4 ở 50oC:
Gọi \(m_{FeSO_4}=a\left(g\right)\Rightarrow m_{H_2O}=200-a\left(g\right)\)
Vì \(S_{FeSO_4\left(50^oC\right)}=48,6\left(g\right)\Rightarrow\dfrac{a}{200-a}.100=48,6\)
\(\Leftrightarrow100a=9720-48,6a\)
\(\Leftrightarrow148,6a=9720\)
\(\Leftrightarrow a=65,41\)
\(\Rightarrow m_{H_2O}=200-65,41=134,59\left(g\right)\)
* Trong dd FeSO4 ở 10oC:
_ \(m_{FeSO_4}=65,41-152x\left(g\right)\)
_ \(m_{H_2O}=134,59-126x\left(g\right)\)
\(\Rightarrow\dfrac{65,41-152x}{134,59-126x}.100=20,5\)
\(\Rightarrow x=0,3\)
\(\Rightarrow m_{FeSO_4.7H_2O}=0,3.278=83,4\left(g\right)\)
