$\begin{array}{c|cc} \rm{\times \;1}&\rm{\mathop{S}\limits^{0}\longrightarrow\mathop{S}\limits^{+6}+6e}\\\rm {\times\;6}&\rm{\mathop{N}\limits^{+5}+1e\longrightarrow\mathop{N}\limits^{+4}}\\\end{array}$

`=>`$\rm S+6HNO_3 \to H_2SO_4+6NO_2+2H_2O$