reaction of pottasium iodide and hydrogen (partial eqation method )
Answers
Since, no matter is destroyed or created during chemical reaction, i.e. energy is never destroyed nor created, there must be equal number of element present in product side as it was in reactant side. That is the reason why we need to balance chemical reaction. Balancing a chemical equation is done by putting suitable integer before the elements or compounds in both reactant and product side.
There are two methods of balancing chemical equation:
1.Hit and Trail Method
2.Partial equation method.
Hit and Trail method: In this method the equation is balanced by trial and error methods. There is no definite rules to balance the equation but simple guessing. Generally hit and trial method is applicable for simple chemical reaction.
H2 + Cl2 → 2HCL
Following step should be noted while balancing a chemical equation:
1.The atom which occurs at minimum number of places on both sides should be selected first and the one occurring maximum number of times should be taken last of all. Let’s illustrate this by following equation:
Na+ H2O → NaOH +H2
Let’s look at each element, Na and oxygen is in same number in both product and reactant side, but there is two hydrogen atom in reactant side while in product side there is three. So let’s try to balance the number of hydrogen atom.
If we multiply H2O by 2 in L.H.S, then number of hydrogen becomes 4, and that of oxygen becomes
2. IN the product side, if we also multiply NaOH by 2, then total hydrogen becomes 4 and oxygen becomes
2. So hydrogen and oxygen in both side becomes equal, i.e balanced. However, while multiplying NaOH in product side by 2, the number of Na becomes 2 in product side, but it is only one in reactant side. So, to balance this, we again multiply Na in reactant side by two, so that overall number of atoms of element becomes equal.
So, final balanced chemical equation becomes,
2Na + 2H2O → 2NaOH +H2
Partial equation method:
Partial equation method is used for balancing complex chemical equations. There are chemical equation which involves many steps and reacting elements occur in more than one products in the product side. In such cases, balancing by Hit and Trial method is difficult. That is why partial equation method is used to balance such chemical equations.
In Partial equation method, equation is first divided into partial equation, which are simply probable steps that might occur in the chemical reaction. These probable steps are then balanced by hit and trail method and finally added. Following steps are applied in balancing chemical equation by partial equation method.
At first, different probable steps are written for the given chemical equation. These probable steps are simply the partial chemical equation which we can write for easily balancing the reactants and product. Note that the probable steps may or may not occur in real.
After breaking down the probable steps for the chemical equation, the partial equations are individually balanced by using Hit and Trial Method.
Such balanced partial equations are multiplied by suitable integer. This is done if required, so that the elements which are not formed in the product side of the overall chemical equation is canceled out.
Finally, the balanced partial equations are added to get the final overall balanced