Question

Which of the following reactions is not correct?

• A. $2Mn{O}_2+4KOH+O_2$
  $\downarrow$
  $4KMn{O}_4+2H_{2}O$
• B. $Mn{O}_4^{-}+8H^{+}5F{e}^{2+}$
  $\downarrow$
  $5F{e}^{3+}+n^{2+}+4H_{2}O$
• C. $2Mn{O}^{4-}+5C_2{O}_4^{2-}+16H^{+}$
  $\downarrow$
  $2M{n}^{2+}+10C{O}_2+8H_{2}O$
• D. $2N{a}_{2}Cr{O}_4+H^{+}$
  $\downarrow$
  $N{a}_{2}C{r}_2{O}_7+2N{a}^{+}+H_{2}O$

Answer 1

The correct option is A $2Mn{O}_2+4KOH+O_2$

$\downarrow$
$4KMn{O}_4+2H_{2}O$
Among the given reactions,
$2MN{O}_2+4KOH+O_2⟶4KMn{O}_4+2H_{2}O$ is incorrect.
This reaction gives potassium manganate as the product and not potassium permanganate.
$2MN{O}_2+4KOH+O_2⟶2K_{2}Mn{O}_4+2H_{2}O$ is the correct reaction.