Answer : The compound contains the highest percentage of lead (by mass) is, PbS.
Explanation :
To calculate the percentage of lead in sample, we use the equation:

<u>For
:</u>
Mass of
= 239.3 g
Mass of Pb = 207.2 g
Putting values in above equation, we get:

The percentage of lead in the
is 86.58 %.
<u>For
:</u>
Mass of
= 267.2 g
Mass of Pb = 207.2 g
Putting values in above equation, we get:

The percentage of lead in the
is 77.55 %.
<u>For
:</u>
Mass of
= 259.7 g
Mass of Pb = 207.2 g
Putting values in above equation, we get:

The percentage of lead in the
is 79.78 %.
<u>For
:</u>
Mass of
= 545.3 g
Mass of Pb = 207.2 g
Putting values in above equation, we get:

The percentage of lead in the
is 37.99 %.
Hence, from this we conclude that, the compound PbS contains the highest percentage of lead (by mass).