The formula of a compound of lead (Pb) and sulfur (S) was determined using the method in this module. A sample of Pb was weighed into a crucible and covered with finely powdered S. The crucible was covered and heated to allow the Pb and S to react. Additional heating burned off all unreacted S. The crucible was then cooled and weighed. The following data were collected.

Mass of crucible and cover, g (27.889)
Mass of crucible, cover, and Pb, g (32.025)
Mass of crucible, cover, and compound formed, g (32.666)
1) Calculate the mass of Pb reacted.
2) Calculate the mass of compound that formed.
3) Calculate the mass of S reacted.
4) Calculate the number of moles of Pb reacted.
5) Calculate the number of moles of S reacted.
6) Find the simplest whole-number ratio of the number of moles of Pb to the number of moles of S in the compound formed.
7) Write the empirical formula for the compound formed.

1 answer

These should help.
https://socratic.org/questions/how-can-i-calculate-the-empirical-formula-of-magnesium-oxide

http://www.webassign.net/userimages/fgdennis@waynecc/Lab_MgO_Intro.pdf