Data
Table 1: Mass of empty crucible
Measurement |
Mass (g) |
Crucible and lid before heating |
38.355g |
After first heating |
38.348g |
Table 2: Mass of crucible and sample
Measurement |
Mass (g) |
Crucible, lid, and precipitate before heating |
45.167g |
Crucible, lid, and precipitate after first heating |
39.350g |
Crucible, lid, and precipitate after second heating |
39.344g |
Table 3: Determination of the amount of sulfate in the unknown
Parameter |
Value |
Mass of unknown sample (g) |
0.6130g |
Mass of crucible and lid (g) |
38.342g |
Mass of crucible, lid, and precipitate (g) |
39.344g |
Mass of precipitate (g) |
1.002g |
Number of moles of precipitate (mol) |
0.00429mol |
Number of moles of SO4 in precipitate (mol) |
0.00429mol |
Mass of SO4 in precipitate (g) |
0.422g |
Percent SO4 in precipitate (%) |
68.8% |
Table 4: Possible unknowns
Formula |
Formula Weight (g/mol) |
Content (%) |
Solubility in Water |
Li2SO4 |
109.98 |
87.4% |
Yes |
Na2SO4 |
142.08 |
67.6% |
Yes |
Na2SO4*H2O |
160.1 |
60.0% |
Yes |
K2SO4 |
174.3 |
55.1% |
Yes |
CaSO4 |
136.18 |
70.6% |
No |
MgSO4 |
120.41 |
79.8% |
Yes |
SrSO4 |
183.72 |
52.3% |
No |