Question

Calculate the percentage by mass of lead in pbco3.

a.17.96
b.22.46
c.73.05
d.77.54
e.89.22

Answer 1

pb/pbco3*100
207/207+12+48
207/267*100
=77.53%

Answer 2

The correct answer is d.

Step-by-step explanation:

Step 1: First we must obtain the molecular weight of
`PbCO_(3)` and Pb.

`PM_{PbCO_(3) }` = 267,21
`(g)/(mol)`

`PM_(Pb)` = 207,2
`(g)/(mol)`

Step 2: We can now calculate the percentage of lead in a
`PbCO_(3)` molecule by stating a simple rule of three:

`PM_{PbCO_(3) }` --> 100%.

`PM_(Pb)` --> X

%Pb =
`\frac{PM_(Pb)}{ PM_{PbCO_(3) }} * 100%`

%Pb =
`(207.2 (g)/(mol))/(267.21 (g)/(mol)) * 100%`

%Pb = 77,54 %

Have a nice day!