SAT Chemistry question: The best way to seperate potassium iodide from a mixture of iron fillings, sand and potassium iodide is by: A. Sublimation B. Using a magnet C. Extraction with water D. Using hydrofluroric acid E. Using a sieve Could you please let me know which one is correct, and also why the other 4 choices are incorrect? Thanks! Solution C. Extraction with water ------------------------------------ Potassium iodide is a ionic salt and is highly soluble in water, while iron fillings and sand are insoluble, so potassium iodide can be dissolved in water and extracted. Sublimation cannot be used since potassium iodide is not sublimable. Magnet, iron fillings get separated not potassium iodide. Hydrofluoric acid, potassium iodide get converted to potassium fluoride, and iron reacts with fluoride and iron fluoride will form. Sieve will separate sand .

1. SAT Chemistry question:
The best way to seperate potassium iodide from a mixture of iron fillings, sand and potassium
iodide is by:
A. Sublimation
B. Using a magnet
C. Extraction with water
D. Using hydrofluroric acid
E. Using a sieve
Could you please let me know which one is correct, and also why the other 4 choices are
incorrect? Thanks!
Solution
C. Extraction with water
------------------------------------
Potassium iodide is a ionic salt and is highly soluble in water, while iron fillings and sand are
insoluble, so potassium iodide can be dissolved in water and extracted.
Sublimation cannot be used since potassium iodide is not sublimable.
Magnet, iron fillings get separated not potassium iodide.
Hydrofluoric acid, potassium iodide get converted to potassium fluoride, and iron reacts with
fluoride and iron fluoride will form.
Sieve will separate sand