Which of the following involves a transfer of electrons?

PCl3 + Cl2 → PCl5
CO2 + 2LiOH → Li2CO3 + H2O
FeCl2 + 2NaOH → Fe(OH)2 + 2NaCl
NaOH + HCl → NaCl + H2O

1 answer

To determine which of the given reactions involves a transfer of electrons, we need to look for redox reactions where oxidation states of atoms change, indicating that electrons are being transferred.

  1. PCl3 + Cl2 → PCl5

    • In this reaction, phosphorus is oxidized from +3 in PCl3 to +5 in PCl5, and chlorine is reduced from 0 in Cl2 to -1 in PCl5. Therefore, this reaction involves a transfer of electrons.
  2. CO2 + 2LiOH → Li2CO3 + H2O

    • This reaction does not involve a change in oxidation states of the elements involved; thus, it does not involve a transfer of electrons.
  3. FeCl2 + 2NaOH → Fe(OH)2 + 2NaCl

    • In this reaction, iron remains in the +2 oxidation state throughout, thus there is no transfer of electrons.
  4. NaOH + HCl → NaCl + H2O

    • This is an acid-base neutralization reaction. There are no changes in oxidation states, so no electrons are transferred.

Based on the analysis, the reaction that involves a transfer of electrons is:

PCl3 + Cl2 → PCl5.