PTHH \(\left(NH_4\right)_2SO_4+2MOH\rightarrow M_2SO_4+2NH_3+2H_2O\\ 0,1mol-0,2mol\leftarrow0,1mol-0,2mol-0,2mol\)
\(n_{NH_3}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
\(m_{M_2SO_4}=m_{ran}=17,4\left(g\right)\)
\(M_{M_2SO_4}=\dfrac{17,4}{0,1}=174\) (g/mol)
\(\Leftrightarrow M_M=39\) (g/mol) Vậy kim loại M là Kali.
\(m_{\left(NH_4\right)_2SO_4}=0,1.132=13,2\left(g\right)\)