Question

Perchloroethylene, also known as perc, is the solvent used in most dry cleaning. It consists of C and Cl. Determine the empirical formula of perchloroethylene given that a 2.58−g sample yields 1.37 g CO2 in a combustion analysis experiment

Answer 1

Answer:

CCl₂

Explanation:

Let us calculate the mass of carbon present in 100 grams of sample.

The formula to calculate the mass of carbon we can use the following formula.

$\frac{12XmassofcarbondioxideX100}{44Xmassofsample}=\frac{12X1.37X100}{2.58x44}=14.5$

The mass of chlorine in the sample = 100-14.5 = 85.5g

Let us calculate the moles of each element:

moles of carbon = $\frac{mass}{atomicmass}=\frac{14.5}{12}=1.208$

Moles of chlorine = $\frac{mass}{atomicmass}=\frac{85.5}{35.5}=2.41$

The mole ratio is :

C:Cl = 1.208:2.41 = 1:2

So the empirical formula of the compound must be CCl₂