3.
下列氧化还原反应中,实际参加反应的氧化剂与还原剂的物质的量之比正确的是\(\rm{(}\) \(\rm{)}\)
\(\rm{①KClO_{3}+6HCl(}\)浓\(\rm{)═KCl+3Cl_{2}↑+3H_{2}O}\);\(\rm{1∶6}\)
\(\rm{②Fe}\)\(\rm{{\,\!}_{2}}\)\(\rm{O}\)\(\rm{{\,\!}_{3}}\)\(\rm{+2Al}\)\(\rm{ \overset{高温}{=} }\)\(\rm{Al}\)\(\rm{{\,\!}_{2}}\)\(\rm{O}\)\(\rm{{\,\!}_{3}}\)\(\rm{+2Fe}\);\(\rm{1∶2}\)
\(\rm{③SiO}\)\(\rm{{\,\!}_{2}}\)\(\rm{+3C}\)\(\rm{ \overset{高温}{=} }\)\(\rm{SiC(}\)硅为\(\rm{+4}\)价\(\rm{)+2CO↑}\);\(\rm{1∶2}\)
\(\rm{④3NO}\)\(\rm{{\,\!}_{2}}\)\(\rm{+H}\)\(\rm{{\,\!}_{2}}\)\(\rm{O═2HNO}\)\(\rm{{\,\!}_{3}}\)\(\rm{+NO}\);\(\rm{2∶1}\)