Answer: Between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.
The actual number of atoms of each element present in the molecule of the compound is represented by the formula known as molecular formula.
Molar mass of the unknown compound = 223.94 g/mol (given)
Mass of each element present in the unknown compound is determined as:
- Mass of carbon,
:

- Mass of hydrogen,
:

- Mass of chlorine,
:

Now, the number of each element in the unknown compound is determined by the formula:

- Number of moles of
:

- Number of moles of
:

- Number of moles of


Dividing each mole with the smallest number of mole, to determine the empirical formula:


Multiplying with 2 to convert the numbers in formula into a whole number:
So, the empirical formula is
.
Empirical mass = 
In order to determine the molecular formula:
n = 
n = 
So, the molecular formula is:

More collisions occur making the particles used up