Answer : The mass of chlorine present in sample is 12.32 kilograms.
Explanation : Given,
Mass of
= 21 kg = 21000 g (1 kg = 1000 g)
First we have to calculate the moles of
.
Molar mass of
= 121 g/mole

Now we have to calculate the moles of chlorine.
In the molecule
, there are 1 mole of carbon, 2 moles of fluorine and 2 moles of chlorine.
As, 1 mole of
contains 2 moles of chlorine
So, 173.5 moles of
contains
moles of chlorine
Now we have to calculate the mass of chlorine.

Molar mass of chlorine = 35.5 g/mole

Therefore, the mass of chlorine present in sample is 12.32 kilograms.