# Question #e2fb6

##### 1 Answer

#### Explanation:

As you know, a compound's empirical formula tells you the **smallest whole number ratio** that exists between the elements that make up said compound.

By comparison, the **molecular formula** tells you the **exact number** of atoms of each element that makes up the compound.

In essence, the molecular formula is a **multiple** of the empirical formula.

Your goal when dealing with such problems will be to determine **how many** empirical formulas are needed to get to the molecular formula.

Notice that the compound is said to have a **molar mass** of *multiple* of the empirical formula, you can use the **molar mass** of the empirical formula to get the multiplication factor that exists between the two.

The empirical formula is said to be

#overbrace(1 xx "14.007 g/mol")^(color(red)("1 atom of N")) + overbrace(2 xx "15.9994 g/mol")^(color(purple)("2 atoms of O")) = "46.006 g/mol"#

This means that you have

#46.006 color(red)(cancel(color(black)("g"))) xx color(blue)(n) = 92 color(red)(cancel(color(black)("g")))#

This will get you

#color(blue)(n) = 92/46.006 = 1.9997 ~~ 2#

Therefore, the **molecular formula** for your compound is

#("NO"_2)_color(blue)(2) = color(green)("N"_2"O"_4) -># dinitrogen tetroxide