Balance the following equation by partial equation method:-
P4 + HNO3= H3PO4 + NO2 + H2O
P4 ==> H3PO4
HNO3 ==> NO2
Want anser
P4 + HNO3 ---------> H3PO4 + NO +H2O
-> P4 + H2O -> H3PO4
Then using hit and trial method
P4 + H2O -> 4H3PO4 + 10[O]
(addition of 10 atoms of oxygen i.e. nascent oxygen to make the equation balanced)
-> HNO3 -> NO2 + H2O
Again using hit and trial method
2HNO3 +[O] -> 2NO2 + H2O
(addition of 1 atom of nascent oxygen to make the equation balanced)
NOTE : THE SAME EXTRA ATOM HAS TO BE MULTIPLIED ON BOTH THE SIDES AS PER THE SITUATION AND MUST BE CUT AT LAST
Now adding both the equations to make a single balanced equation
P4 + H2O -> 4H3PO4 + 10[O]
+ 2HNO3 +[O] -> 2NO2 + H2O } ×10
————————————————————
P4 + 20HNO3 -> 4H3PO4 + 2NO + 9H2O
AT last the oxygens and 1 water molecule get cancelled and the above answer remains
Hence done......=)
To balance the given equation P4 + HNO3 = H3PO4 + NO2 + H2O using the partial equation method, follow these steps:
Step 1: Group the reactants and products by the different elements involved.
- On the reactant side, we have phosphorus (P) and nitrogen (N).
- On the product side, we have phosphorus (P), nitrogen (N), oxygen (O), and hydrogen (H).
Step 2: Balance the atoms other than hydrogen and oxygen.
- Start by balancing the phosphorus (P) atoms. There are four phosphorus (P) atoms on the reactant side, but only one (P) on the product side. Add a coefficient of 4 in front of H3PO4 to balance the phosphorus atoms: P4 + HNO3 = 4H3PO4 + NO2 + H2O
Step 3: Balance the hydrogen (H) atoms.
- There are 4 hydrogen (H) atoms on the reactant side, but 12 hydrogen (H) atoms on the product side. To balance hydrogen (H), add a coefficient of 6 in front of H2O: P4 + HNO3 = 4H3PO4 + NO2 + 6H2O.
Step 4: Balance the nitrogen (N) atoms.
- There is one nitrogen (N) atom on the reactant side, but one nitrogen (N) atom on the product side. The nitrogen (N) atoms are already balanced.
Step 5: Balance the oxygen (O) atoms.
- On the reactant side, there are three oxygen (O) atoms from HNO3, totaling 4 oxygen (O) atoms due to the H3PO4 already balanced. On the product side, there are four oxygen (O) atoms from H3PO4 and two oxygen (O) atoms from H2O, totaling 6 oxygen (O) atoms. To balance the oxygen (O) atoms, add a coefficient of 3/2 in front of HNO3: P4 + 3/2HNO3 = 4H3PO4 + NO2 + 6H2O.
Therefore, the balanced equation is:
P4 + 3/2HNO3 = 4H3PO4 + NO2 + 6H2O.