Question

In the redox reaction: $xKMn{{O}_{4}}+yN{{H}_{3}}\to KN{{O}_{3}}+Kn{{O}_{2}}+KOH+{{H}_{2}}O.$
A.$x=4,y=6$
B.$x=3,y=8$
C.$x=8,y=6$
D.$x=8,y=3$

Answer 1

We know that from the reaction, we can identify that Lead oxide is reduced to lead and ammonia is being oxidized to nitrogen. Oxidation and reduction reaction occurs Identification of loss or gain of electrons helps to detect which element is being oxidized or reduced.

Complete answer:
Firstly, we have to look onto steps to be considered while balancing a chemical equation. Balancing a chemical equation is a mandatory thing which we should be aware of while writing chemical reactions. That balancing should result in an equal amount of reactants and products, then only we can say it is balanced. One important law related with this balancing is the law of conservation of mass where the amount of reactants should be accurately enough to produce equal amounts of products which is used as a principle in large factories for proper profitable production which are relatively concerned with balanced chemical equations. Hence we need to balance it. Let us look onto the steps to be followed to balance the above unbalanced equation.
Unbalanced chemical equation
Making a separate list of both reactant and product sides.
Identifying atoms of each element.
Coefficient is placed in front of molecules.
Checking the equation.
Balanced equation is $8KMn{{O}_{4}}+3N{{H}_{3}}\text{ }\to 8Mn{{O}_{2}}+3KN{{O}_{3}}+5KOH+2{{H}_{2}}O.$
Therefore the correct answer is option D.

Note:
Remember that if an oxidation number decreases in a reaction, it is reduced. Similarly, if the oxidation number increases in a reaction, it is oxidized. Here, $KMn{{O}_{4}}$ is reduced to lead and ammonia is being oxidized to nitrogen Calculating reduction reaction of lead, oxidation reaction of ammonia and by solving those reaction we can get the final required equation.