$\overset{+1}{\mathop{H}}\,\overset{X}{\mathop{Cl}}\,\,:\,\,1\left( +1 \right)+X=0\Rightarrow \,\,X=-1$
$\overset{+1}{\mathop{H}}\,\overset{X}{\mathop{Cl}}\,{{\overset{-2}{\mathop{O}}\,}_{4}}\,:\,\,1\left( +1 \right)+X+4\left( -2 \right)=0\Rightarrow \,\,X=+7$
$\overset{+1}{\mathop{I}}\,\overset{X}{\mathop{Cl}}\,\,:\,\,1\left( +1 \right)+X=0\Rightarrow \,\,X=-1$
${{\overset{X}{\mathop{Cl}}\,}_{2}}\overset{-2}{\mathop{O}}\,:\,\,\,\,2\left( X \right)+1\left( -2 \right)\,\,=0\,\,\,\,\,\,\Rightarrow \,\,\,X=+1$
$Cr _2 O _7^{2-}+ XH ^{+}+6 Fe ^{2+} \rightarrow YCr ^{3+}+6 Fe ^{3+}+ ZH _2 O$
$X , Y$ અને $Z$ નો સરવાળો $......$ છે.
${P_4} + 10C{l_2}\xrightarrow{\Delta }PC{l_5}$