Question

Hey frnds....

here is a question for you.....

Solve the attached.... redox reaction by ion electron method only....

Appropriate answer will be marked brainliest....

Answer 1

Balance all other atoms except hydrogen and oxygen. We can use any of the species that appear in the skeleton equations for this purpose. Keep in mind that reactants should be added only to the left side of the equation and products to the right.


P4 → 4H2PO2-

 


P4 → 4PH3

 

 Balance the oxygen atoms. Check if there are the same numbers of oxygen atoms on the left and right side, if they aren't equilibrate these atoms by adding water molecules.



P4 + 8H2O → 4H2PO2-

 



P4 → 4PH3

 

Balance the hydrogen atoms. Check if there are the same numbers of hydrogen atoms on the left and right side, if they aren't equilibrate these atoms by adding protons (H+).



P4 + 8H2O → 4H2PO2- + 8H+

 



P4 + 12H+ → 4PH3

 

 For reactions in a basic medium, add one OH- ion to each side for every H+ ion present in the equation. The OH- ions must be added to both sides of the equation to keep the charge and atoms balanced. Combine OH- ions and H+ ions that are present on the same side to form water.



P4 + 8H2O + 8OH- → 4H2PO2- + 8H2O

 



P4 + 12H2O → 4PH3 + 12OH-

 

Step 4. Balance the charge. To balance the charge, add electrons (e-) to the more positive side to equal the less positive side of the half-reaction. It doesn't matter what the charge is as long as it is the same on both sides.



P4 + 8H2O + 8OH- → 4H2PO2- + 8H2O + 4e-

 



P4 + 12H2O + 12e- → 4PH3 + 12OH-

 

Make electron gain equivalent to electron lost. The electrons lost in the oxidation half-reaction must be equal the electrons gained in the reduction half-reaction. To make the two equal, multiply the coefficients of all species by integers producing the lowest common multiple between the half-reactions.



P4 + 8H2O + 8OH- → 4H2PO2- + 8H2O + 4e-

| *3



P4 + 12H2O + 12e- → 4PH3 + 12OH-

| *1



3P4 + 24H2O + 24OH- → 12H2PO2-+ 24H2O + 12e-

 



P4 + 12H2O + 12e- → 4PH3 + 12OH-

 

Add the half-reactions together. The two half-reactions can be combined just like two algebraic equations, with the arrow serving as the equals sign. Recombine the two half-reactions by adding all the reactants together on one side and all of the products together on the other side.

4P4 + 36H2O + 24OH- + 12e- → 12H2PO2- + 4PH3 + 24H2O + 12OH- + 12e-


 Simplify the equation. The same species on opposite sides of the arrow can be canceled. Write the equation so that the coefficients are the smallest set of integers possible.

P4 + 3H2O + 3OH- → 3H2PO2- + PH3


Finally, always check to see that the equation is balanced. First, verify that the equation contains the same type and number of atoms on both sides of the equation.

P4 + 3H2O + 3OH- → 3H2PO2- + PH3