This is an oxidation-reduction (redox) reaction:

* S0 + 2 e- → S-II (reduction)*

* Ni0 - 2 e- → NiII (oxidation)*

** S** is an oxidizing agent,

**is a reducing agent.**

*Ni*### Word equation

* mixed sulfur + nickel → nickel(II) sulfide*

### Input interpretation

* S + Ni → SNi*

* Mixed sulfur nickel nickel(II) sulfide*

### Balanced equation

Balance the chemical equation algebraically:

* S + Ni → SNi*

Add stoichiometric coefficients, c1, to the reactants and products:

* c1S + c2Ni → c3SNi*

Set the number of atoms in the reactants equal to the number of atoms in the products for** S **and

*Ni:**S: c1 = c3*

*Ni: 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*

Substitute the coefficients into the chemical reaction to obtain the balanced

equation:

** Answer**:

* S + Ni → SNi*