1.
\(NH_3\uparrow+H_2O\rightarrow NH_4^++OH^-\)
\(H^++OH^-\rightarrow H_2O\)
\(Fe^{2+}+2OH^-\rightarrow Fe\left(OH\right)_2\downarrow\)
\(Cu^{2+}+2OH^-\rightarrow Cu\left(OH\right)_2\downarrow\)
\(Al^{3+}+3OH^-\rightarrow Al\left(OH\right)_3\downarrow\)
\(Al\left(OH\right)_3\downarrow+OH^-\rightarrow AlO_2^-+2H_2O\)
2.
\(n_{NH_3}=n_{NH_4^+}=0,15.1=0,15\left(mol\right)\)
\(\Rightarrow V_{NH_3}=0,15.22,4=3,36\left(l\right)\)
3.
\(NH_3\uparrow+H_2O\rightarrow NH_4^++OH^-\)
\(Fe^{2+}+2OH^-\rightarrow Fe\left(OH\right)_2\downarrow\)
\(Al^{3+}+3OH^-\rightarrow Al\left(OH\right)_3\downarrow\)
\(Al\left(OH\right)_3\downarrow+OH^-\rightarrow AlO_2^-+2H_2O\)
\(n_{Fe\left(OH\right)_2}=n_{FeCl_2}=0,15\left(mol\right)\)
\(\Rightarrow m_{\downarrow}=m_{Fe\left(OH\right)_2}=0,15.90=13,5\left(g\right)\)