Indicate whether the following balanced equations involve oxidationfreduction.

Check all that apply.

$2H_{2}S{O}_4(aq)+2$NaBr$(s)B{r}_2(l)+S{O}_2(g)+N{a}_{2}S{O}_4(aq)+2H_{2}O(l)$

$2AgN{O}_3(aq)+CoC{l}_2(aq)2$AgCl$(s)+Co(N{O}_3{)}_2(aq)$

$2F{e}_3{O}_4(s)6$FeO$(s)+O_2(g)$