Question

The balanced equation for the reaction of dilute nitric acid with copper is:
A) $3Cu + 8HN{O_3}\left( {dil.} \right) \to 3Cu{\left( {N{O_3}} \right)_2} + 4{H_2}O + 2NO$
B) $Cu + 8HN{O_3}\left( {dil.} \right) \to Cu{\left( {N{O_3}} \right)_2} + 4{H_2}O + 2NO\;$
C) $3Cu + 4HN{O_3}\left( {dil.} \right) \to 3Cu{\left( {N{O_3}} \right)_2} + 4{H_2}O + 2NO$
D) $Cu + 8HN{O_3}\left( {dil.} \right) \to Cu{\left( {N{O_3}} \right)_2} + 2{H_2}O + NO$

Answer 1

As we know that in chemistry, equations play a major role. In the reaction three things are main. There are reactants, products and reaction conditions. The reactants are always on the left side of the equation. If more than one reactant in the equation means by using plus sign. The products are always on the right side of the reaction. Something here also follows. More than one product by using plus sign. In between reactant products are used arrows to find the reaction direction in the equation.

Complete answer:
The balanced chemical equation wise we can predict unknown products in the chemical reaction.
In chemistry, balances the chemical equation means,
We adjust the number moles of reactant and product used to attain an equal number of the same atom in reactant and product in the given chemical reaction.
The chemical reaction of dilute nitric acid with copper is given below,
$Cu + HN{O_3}\left( {dil.} \right) \to Cu{\left( {N{O_3}} \right)_2} + {H_2}O + NO$
The copper metal is once reacted with dilute nitric acid to give the product of cupric nitrate and water.
The balanced chemical reaction for the above discussion is given below,
$3Cu + 8HN{O_3}\left( {dil.} \right) \to 3Cu{\left( {N{O_3}} \right)_2} + 4{H_2}O + 2NO$
For the count of all atoms in the reactant and product side of the chemical reaction is equal.
According to the above discussion, we conclude the balanced equation for the reaction of dilute nitric acid with copper is $3Cu + 8HN{O_3}\left( {dil.} \right) \to 3Cu{\left( {N{O_3}} \right)_2} + 4{H_2}O + 2NO$.

Hence, option A is the correct answer, because it only has a balanced chemical equation.

Note:
In balanced chemical reaction wise, we predict the side product of the reaction. In some cases we are not able to attain balance by changing the mole. In that case we use the number of countable ions in the product and reactant side of the chemical reaction. In chemistry, redox reaction is one of the types of major reactions. In this redox reaction two methods are used to attain the balanced chemical reaction. There are ion-electron methods and the oxidation number method.