Calculate Mass of Chlorine in PbCl4 Sample using Mass Conservation

Published on March 2, 2026

Word-Problem

Determine the mass of Chlorine (Cl) in a 37.11 g sample of PbCl4 by subtracting the given mass of Lead (Pb) from the total sample mass.

Question

This is a stoichiometry problem that can be solved using the Law of Conservation of Mass and the concept of percent composition by mass.

Here is the step-by-step solution:

1. Identify the given information:

2. Determine the mass of Chlorine () in the sample.
Since the sample is composed only of

and

(in the compound

), the total mass is the sum of the masses of its components:

We can rearrange this equation to find the mass of

Substitute the given values:

3. Final Answer Check (Optional: Calculate theoretical percent composition to verify consistency, although not required by the question):

First, we need the molar masses:

The theoretical mass percentage of

is:

The actual mass percentage of

in the sample is:

Since the percentages are very close, the initial calculation based on the conservation of mass is correct for the given sample.

The mass of

in the

sample is

The final answer is