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

* 2 NV + 4 e- → 2 NIII (reduction)*

* 2 O-II - 4 e- → 2 O0 (oxidation)*

** Ca(NO3)2** is an

**oxidizing**agent,

**is a**

*Ca(NO3)2***reducing**agent.

### Word equation

* calcium nitrate → calcium nitrite + oxygen*

### Input interpretation

* Ca(NO3)2 → Ca(NO2)2 + O2*

* calcium nitrate calcium nitrite oxygen*

### Balanced equation

Balance the chemical equation algebraically:

* Ca(NO3)2 → Ca(NO2)2 + O2*

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

* c1Ca(NO3)2 → c2Ca(NO2)2 + c3O2*

Set the number of atoms in the reactants equal to the number of atoms in the products for ** Ca, N **and

*O:**Ca: c1 = c2*

*N: 2c1 = 2c2*

*O: 6c1= 4c2+2c3*

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*

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

**Answer**:

* Ca(NO3)2 → Ca(NO2)2 + O2*