Is 2Ca(s) + O2(g) —> 2CaO(s) a redox reaction? What is the reducing agent and what is the oxidizing agent?
Yes, the reaction 2Ca(s) + O2(g) -> 2CaO(s) is a redox (reduction-oxidation) reaction.
In this reaction, calcium (Ca) is oxidized from an oxidation state of 0 to +2 (Ca -> Ca2+), while oxygen (O2) is reduced from an oxidation state of 0 to -2 (O2 -> 2O2-).
The reducing agent is the substance that undergoes oxidation, which in this case is Ca. The oxidizing agent is the substance that undergoes reduction, which in this case is O2.