Decantation
Centrifugation
Filtration
Evaporation
Atomic number should be the answer
There are 5 significant figures
2C4H10 + 13O2 = 8CO2 + 10H2O
1. (2.06g C4H10)/(58.12 g/mol C4H10) = 0.035mol C4H10
2. (0.035molC4H10)(10 mol H2O/2mol C4H10) = 0.177mol H2O
3. (0.177mol H2O)(18.01g/mol H2O) = 3.19g H2O
Atoms of sulfur = 9.60⋅g32.06⋅g⋅mol−1×6.022×1023⋅mol−1 . Because the units all cancel out, the answer is clearly a number, ≅2×1023 as required.