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Redox Reactions — Chemistry STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceChemistryRedox Reactions5 Marks
Question
  1. $\text{MnO}_4^{2-}$ undergoes disproportionation reaction in acidic medium but does not, give reason.
  2. Give one example each of the following redox reaction:
  1. Combination reaction.
  2. Decomposition reaction.
  3. Metal displacement reaction.
✓

Answer

  1. In $\text{MnO}_4^{2-}$ Mn is in +6 oxidation state, it can increase to +7 and decrease to +4 therefore, undergoes disproportionation reaction oxidation as well reduction simultaneously, in $\text{MnO}_4^-$ Mn is in +7. highest oxidation state, can undergo reduction only.
  2.  
  1. Combination reaction:
$\text{S}+\text{O}\xrightarrow{ \ \ \ \ \ }\text{SO}_2\\ 0\ \ \ \ \ \ 0\ \ \ \ +4,-2$
  1. Decomposition reaction:
$2\text{H}_2\text{O}_2\xrightarrow{ \ \ \ }2\text{H}_2\text{O}+\text{O}_2\\ +1-1 \ \ \ \ -2$
  1. Metal displacement reaction:
$\text{Mg}\text{(s)}+\text{CuSO}_4\text{(aq)}\xrightarrow{ \ \ \ \ \ \ }\text{MgSO}_4\text{(aq)}+\text{Cu}\\ \ 0 \ \ \ \ \ \ \ \ \ \ \ +2\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ +2\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 0 $

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