Question

The oxidation states of transition metal atoms in $K_{2}C{r}_2{O}_7,$ $KMn{O}_4$ and $K_{2}Fe{O}_4,$ respectively, are $x,yandz.$ The sum of $x,y$ and $z$ is:


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Answer 1

$K_{2}C{r}_2{O}_7$
$2(+1)+2x+7(-2)=0$
$x=+6$

$KMn{O}_4$
$(+1)+y+4(-2)=0$
$y=+7$

$K_{2}Fe{O}_4$
$2(+1)+z+4(-2)=0$
$z=+6$

So, $x=6$
$y=7$
$z=6$
Therefore, $x+y+z=19$