a, PT: \(Mg\left(OH\right)_2+2HCl\rightarrow MgCl_2+H_2O\)
\(Cu\left(OH\right)_2+2HCl\rightarrow CuCl_2+H_2O\)
\(NaOH+HCl\rightarrow NaCl+H_2O\)
Ta có: nHCl = 0,1.1 = 0,1 (mol)
Theo PT: \(n_{H_2O}=\dfrac{1}{2}n_{HCl}=0,05\left(mol\right)\)
Theo ĐLBTKL, có: m + mHCl = m muối + mH2O
⇒ m = 24,1 + 0,05.18 - 0,1.36,5 = 21,35 (g)
b, Phần không tan là Mg(OH)2 và Cu(OH)2
PT: \(Mg\left(OH\right)_2\underrightarrow{t^o}MgO+H_2O\)
\(Cu\left(OH\right)_2\underrightarrow{t^o}CuO+H_2O\)
\(CuO+CO\underrightarrow{t^o}Cu+CO_2\)
\(MgO+H_2SO_4\rightarrow MgSO_4+H_2O\)
Chất rắn là Cu.
\(\Rightarrow n_{Cu\left(OH\right)_2}=n_{CuO}=n_{Cu}=\dfrac{3,2}{64}=0,05\left(mol\right)=n_{CuCl_2}\)
\(n_{Mg\left(OH\right)_2}=n_{MgO}=n_{MgSO_4}=n_{H_2O}=\dfrac{1,8}{18}=0,1\left(mol\right)=n_{MgCl_2}\)
\(\Rightarrow n_{NaOH}=n_{NaCl}=\dfrac{24,1-m_{MgCl_2}-m_{CuCl_2}}{58,5}=\dfrac{157}{1170}\left(mol\right)\)
⇒ mMg(OH)2 + mCu(OH)2 + mNaOH = 16,07 (g)
⇒ m tạp chất = 21,35 - 16,07 = 5,28 (g)