\(\overset{X}{\mathop{Mn}}\,{{\overset{-1}{\mathop{Cl}}\,}_{2}}:\,X+2\left( -1 \right)=0\,\Rightarrow X=+2\)
\(\overset{X}{\mathop{Mn}}\,{{\overset{-1}{\mathop{O}}\,}_{2}}:\,X+2\left( -2 \right)=0\,\Rightarrow X=+4\)
\(\overset{X}{\mathop{Mn}}\,{{\overset{-1}{\mathop{\left( OH \right)}}\,}_{3}}:\,X+3\left( -1 \right)=0\,\Rightarrow X=+3\)
\(\overset{+1}{\mathop{K}}\,\overset{X}{\mathop{Mn}}\,{{\overset{-2}{\mathop{O}}\,}_{4}}:\,\,1\left( +1 \right)+X+4\left( -2 \right)=0\,\Rightarrow X=+7\)
આથી \(Mn\) ના ઓ.આંકનો વધતો ક્રમ નીચે પ્રમાણે થશે.\(MnC{l_2} < \,Mn{\left( {OH} \right)_3} < \,Mn{O_2} < KMn{O_4}\)
${P_4} + 10C{l_2}\xrightarrow{\Delta }PC{l_5}$
$Fe\, + \,{H_2}O\, \to \,F{e_3}{O_4}\, + \,{H_2}$