Part V Write the (a) half reaction of oxidation, (b) half reaction of reduction, & (c) the balanced redox reaction for all of the chemical reactions listed below. 26. 2Sr + O2 → 2SrO (a) O0 + 2e- → O-2 (b) Sr0 → Sr+2 + 2e- (c) O0 + Sr0 → O-2 + Sr+2

Explanation:

a. Oxidation : 2O + 4e^- > 2O^2-

b. Reduction: 2Sr - 4e- > Sr^2+

c. Balanced redox reaction

2Sr + O2 > 2Sr O

Oxidation and reduction can be defined by various means, addition of oxygen, removal of hydrogen, removal of electrons. For this reaction, this definition is used, oxidation is the loss of electrons while reduction is the gaining of electrons.

In (a) oxidation half reaction, the valency of oxygen is zero and then moves into lossing two electrons resulting into -2 valency.

In (b) reduction half reaction, the valency of Sr is zero and gains electrons resulting into valency of 2.

In the overall redox reaction, Sr and O2 with valency of 0 each reacts together and form SrO with valency of 2 and -2 respectively, which gives 0 and then balances the equation.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.