Q104 / 270 · NDA 2018 (Phase 2) · General Ability

Which one of the followings an oxidation-reduction reaction?

  • A
    $\mathrm{NaOH}+\mathrm{HCl} \rightarrow \mathrm{NaCl}+\mathrm{H}_2 \mathrm{O}$
  • B
    $\mathrm{CaO}+\mathrm{H}_2 \mathrm{O} \rightarrow \mathrm{Ca}(\mathrm{OH})_2$
  • Correct answer
    C
    $2 \mathrm{Mg}+\mathrm{O}_2 \rightarrow 2 \mathrm{MgO}$
  • D
    $\mathrm{Na}_2 \mathrm{SO}_4+\mathrm{BaCl}_2 \rightarrow \mathrm{BaSO}_4+2 \mathrm{NaCl}$

Solution

An oxidation-reduction (redox) reaction is a type of chemical reaction that involves a transfer of electrons between two species. An oxidation-reduction reaction is any chemical reaction in which the oxidation number of a molecule, atom, or ion changes by gaining or losing an electron.

Hence, the correct answer is option: 'C'.

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