I know how to find a and b on this problem but how do I find c? Really would appreciate the help, thanks!

The formula of a compound of iron and sulfur was determined using the method of mass measurements. A sample of iron was weighed into a crucible and covered with finely powdered sulfur. The crucible was covered and heated to allow the iron and sulfur to react. Additional heating burned off all unreacted sulfur. The crucible was then cooled and weighted. The following data was collected.
Mass of crucible and cover: 27.889g
Mass of crucible, cover and iron: 32.025g
Mass of crucible, cover and compound formed: 35.587g
a. Calculate the mass of iron reacted
b. Calculate the mass of compound that formed
c. Calculate the mass of sulfur reacted

c=b-a

To find the mass of sulfur reacted, you can use the given information and the principle of conservation of mass.

Here's how to do it step by step:

1. Calculate the mass of iron reacted (a):
Mass of crucible, cover, and iron = 32.025g
Mass of crucible and cover = 27.889g

a = Mass of crucible, cover, and iron - Mass of crucible and cover
a = 32.025g - 27.889g
a = 4.136g

Therefore, the mass of iron reacted is 4.136g.

2. Calculate the mass of compound that formed (b):
Mass of crucible, cover, and compound formed = 35.587g
Mass of crucible and cover = 27.889g

b = Mass of crucible, cover, and compound formed - Mass of crucible and cover
b = 35.587g - 27.889g
b = 7.698g

Therefore, the mass of compound that formed is 7.698g.

3. Calculate the mass of sulfur reacted (c):
c = Mass of compound that formed - Mass of iron reacted
c = 7.698g - 4.136g
c = 3.562g

Therefore, the mass of sulfur reacted is 3.562g.