Answer:
(i) +3.
(ii) Mn.
Explanation:
Hello,
(i)
Based on the diatomic ion, we solve for the unknown oxidation state of carbon, assuming that the oxygen works with -2, by a change balance:
[tex](C_2O_4)^{-2}\\(C_2^{x} O_4^{-2} )^{-2}\\\\2x-8=-2\\x=+3[/tex]
(ii)
We first must each ion's oxidation states as follows:
[tex]2H^{+} Cl^{-}+ 2K^{+}Mn^{+7}O^{-2}_4 + 3H_2^{+}C_2^{+3}O_4^{-2} --> 6C^{+4}O^{-2}_2 +2Mn^{+4}O_2^{-2} + 2K^{+}Cl^{-} + 4H_2^{+}O^{-2}[/tex]
Then, for the reduction half reaction we identify the manganese as the element decreasing its oxidation state based on:
[tex]Mn^{+7} +3e^{-}-->Mn^{+4}[/tex]
In addition, the carbon is oxidized from +3 to +4 (increase the oxidation state).
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