Question

what is the percent composition of PbCl2?

Answer 1

Answer on Question #64514 - Chemistry - Other

Task:

What is the percent composition of $\mathrm{PbCl}_2$?

Solution:

Standard atomic weight:

$$Ar(Pb) = 207.2;$$ $$Ar(Cl) = 35.45;$$

We find the molar mass PbCl2:

$$M(PbCl_2) = Ar(Pb) + 2 \times Ar(Cl) = 207.2 + 2 \times 35.45 = 278.1\ g/mol$$

Then,

$$w(Pb) = \frac{Ar(Pb)}{M(PbCl_2)} \times 100\% = \frac{207.2}{278.1} \times 100\% = 74.5\%;$$ $$w(Cl) = \frac{2 \times Ar(Cl)}{M(PbCl_2)} \times 100\% = \frac{2 \times 35.45}{278.1} \times 100\% = 25.5\%.$$

Answer:

Percent composition of $\mathrm{PbCl}_2$: 74.5% Pb and 25.5% Cl.

Answer provided by www.AssignmentExpert.com