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

`"4NO"_2("g")+"O"_2("g")+"2H"_2"O("l")` `rarr` `"4HNO"_3("aq")`

Explanation:

This is a synthesis reaction, also called a combination reaction, because two or more reactants produce a single product. You essentially have been given a word equation, which does not give the chemical formulas of each substance. In order to write a chemical equation, you need to determine the chemical formulas of each substance. Then write the equation and balance it.

Reactants
Gaseous nitrogen dioxide: `"NO"_2("g")`
Gaseous oxygen: `"O"_2("g")`
Liquid water: `"H"_2"O"(l)"`

Product
Aqueous nitric acid: `"HNO"_3("aq")`

Balanced Equation

`"4NO"_2("g")+"O"_2("g")+"2H"_2"O("l")` `rarr` `"4HNO"_3("aq")`