Question

The balance chemical equation for the reaction $Cu+HN{{O}_{3}}\to Cu{{(N{{O}_{3}})}_{2}}+NO+{{H}_{2}}O$ involves.
(A) $6HN{{O}_{3}}$
(B) $2HN{{O}_{3}}$
(C) $4HN{{O}_{3}}$
(D) $8HN{{O}_{3}}$

Answer 1

Hint : We know that we can write the chemical equation of the above given chemical reactions, then by applying trial and error methods in order to balance the chemical equation. The condition to balance is the number of a particular element in the reactant should be equal to the number of elements in the product.

Complete Step By Step Answer:
Chemical equation is the representation of a chemical reaction where the reactants react to give products. The law of conservation of mass attributes for balancing a chemical equation. First, we should know what a chemical equation is. The chemical equation is the representation of the chemical reaction in the symbolic form. The reactants are written on the left hand side and the products are written on the right-hand side and there is an arrow from left to the right symbolizing a complete chemical equation. Chemical equation is the representation of a chemical reaction where the reactants react to give products. Applying the law of conservation of mass to a chemical, there is no atom neither destroyed from the reactant side nor created in the product, so the number of elements in the reactant is equal to the number of elements in the product. This is the theory behind balancing chemical equations.
We have been given a chemical equation to solve. We have been given the equation in words and we need to use the appropriate compound symbols and name and complete the balanced equation. The question given to us is
Now, $Cu\to C{{u}^{2+}}+2{{e}^{-}}................(1)$ and $NO_{3}^{-}+4{{H}^{+}}+3{{e}^{-}}................(2)$
For equalizing the electrons Equation $\left( 1 \right)\times 3+$ Equation $\left( 2 \right)\times 2;$

Equation $\left( 1 \right)$	$3Cu$	$\xrightarrow{{}}$	$3C{{u}^{2+}}+6{{e}^{-}}$
Equation $\left( 2 \right)$	$2NO_{3}^{-}+8{{H}^{+}}+6{{e}^{-}}$	$\xrightarrow{{}}$	$2NO+4{{H}_{2}}O$
Result	$3Cu+2NO_{3}^{-}+8{{H}^{+}}$	$\xrightarrow{{}}$	$3C{{u}^{2+}}+2NO+4{{H}_{2}}O$

But, $8{{H}^{+}}+8NO_{3}^{-}\to 8HN{{O}_{3}}$
Thus, $6NO_{3}^{2-}$ combine with $C{{u}^{2+}}$ and the balance equation is:
$3Cu+8HN{{O}_{3}}\to 3Cu{{(N{{O}_{3}})}_{2}}+2NO+4{{H}_{2}}O$
Therefore, the correct answer is option D.

Note :
Remember that in this, the reactants and the products are expressed in their chemical formulas. It is a way to represent the chemical equation in an easier and more understandable way. A chemical equation is based on the law of the conservation of the mass which states that the mass can neither be created nor be destroyed but can be transformed from one form to another.