\(\begin{array}{l}1.\,\,Be{F_2} \to B{e^{2 + }} + 2{F^ - }\\\,\,\,\,\,HBr{O_4} \to {H^ + } + BrO_4^ - \\\,\,\,\,\,{K_2}Cr{O_4} \to 2{K^ + } + CrO_4^{2 - }\\2.\,\,HBrO \mathbin{\lower.3ex\hbox{$\buildrel\textstyle\rightarrow\over{\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}}$}} {H^ + } + Br{O^ - }\\\,\,\,\,\,HCN \mathbin{\lower.3ex\hbox{$\buildrel\textstyle\rightarrow\over{\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}}$}} {H^ + } + C{N^ - }\end{array}\)
