### This is an **oxidation-reduction** (redox) reaction:

* Na0 - 1 e- → NaI (oxidation)*

*Na0 - 1 e- → NaI (oxidation)*

* 2 HI + 2 e- → 2 H0 (reduction)*

*2 HI + 2 e- → 2 H0 (reduction)*

* O-II - 1 e- → O-I (oxidation)*

*O-II - 1 e- → O-I (oxidation)*

*Na* is a **reducing** agent, *H2O* is an **oxidizing** agent, *H2O* is a **reducing** agent.

### Input interpretation

* Na + H2O → NaO + H2*

* Sodium water hydrogen*

### Balanced equation

Balance the chemical equation algebraically:

* Na + H2O → NaO + H2*

Add stoichiometric coefficients, c;, to the reactants and products:

* c1 Na + c2 H2O → c3NaO + c4 H2*

Set the number of atoms in the reactants equal to the number of atoms in the products for **Na, H **and **O:**

*Na: c1 =c3*

*H: 2c2=2c4 *

*O: c2=c3*

Since the coefficients are relative quantities and underdetermined, choose a coefficient to set arbitrarily. To keep the coefficients small, the arbitrary value is ordinarily one. For instance, set **c1 = 1** and solve the system of equations for the remaining coefficients:

* c1 = 1 c2=1*

* c3=1 c4=1*

Substitute the coefficients into the chemical reaction to obtain the balanced equation:

Answer:

* Na + H2O → NaO + H2*