Question

How do you write a chemical formula for the following scenario: Nitric acid is a component of acid rain that forms when gaseous nitrogen dioxide pollutant reacts with gaseous oxygen and liquid water to form aqueous nitric acid?

Answer 1

Hint: As we know that this reaction is basically a synthesis reaction, which is also called a combination reaction because here we can see that two or more reactants combine to produce a single product. In order to determine the chemical formula, we need to first write the chemical formula of every substance. Then we will write the equation and balance it.

Complete answer:
- As we know that oxidation states basically indicate the hypothetical charge on the atom that is given on the basis of gain of electrons or loss of electrons to form a chemical bond.
- It is found that the oxidation number of an atom is equal to the total number of electrons that is added to the element or is removed from an element to reach the present state.
- As we know that the reactants for this reaction are gaseous nitrogen dioxide ($N{{O}_{2}}$)
, oxygen (${{O}_{2}}$) and liquid water (${{H}_{2}}O$).The product obtained is aqueous nitric acid that is $HN{{O}_{3}}$ .
- Now, we can write the balanced chemical equation as:
 $4N{{O}_{2}}\left( g \right)+{{O}_{2}}\left( g \right)+{{H}_{2}}O\left( l \right)\to 4HN{{O}_{3}}\left( aq \right)$
 -Hence we can write a chemical formula for the scenario: Nitric acid is a component of acid rain that forms when gaseous nitrogen dioxide pollutant reacts with gaseous oxygen and liquid water to form aqueous nitric acid as: $4N{{O}_{2}}\left( g \right)+{{O}_{2}}\left( g \right)+{{H}_{2}}O\left( l \right)\to 4HN{{O}_{3}}\left( aq \right)$

Note:
- We should note that while writing the chemical formula we must know in which form the atom exists whether di, mono or triatomic, and we must also know the oxidation states. All these facts will help us to get the correct answer.