This is an oxidation-reduction (redox) reaction:
2 P0 + 6 e- → 2 P-III (reduction)
3 Mg0 - 6 e- → 3 MgII (oxidation)
P is an oxidizing agent, Mg is a reducing agent.
Word equation
magnesium + red phosphorus → magnesium phosphide
Input interpretation
3Mg + P2 → Mg3P2
Magnesium red phosphorus magnesium phosphide
Balanced equation
Balance the chemical equation algebraically:
3Mg + P2 → Mg3P2
Add stoichiometric coefficients, c1, to the reactants and products:
c13Mg + c2P2 → c3Mg3P2
Set the number of atoms in the reactants equal to the number of atoms in the products for Mg and P:
Mg: c1 = 3c3
P: c2 = 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 c3 = 1 and solve the system of equations for the remaining coefficients:
c1 = 3 c2=2
c3=1
Substitute the coefficients into the chemical reaction to obtain the balanced
equation:
Answer:
3Mg + P2 → Mg3P2
