3 fix formatting+clarify JEE+fix tags

How to determine order of nucleophilicity among commonly used nucleophiles? For eg.example, in Finklestein reaction, $$\ce{NaI}$$ (reagent) - taken in acetone  (solvent) - displaces $$\ce{SH-}$$ ion from alkyl group via SN2SN2 mechanism to form an alkyl iodide. But in a separate question we may be asked to write the product formed when $$\ce{NaSH}$$ reacts with an alkyl iodide in the presence of acetone. Since I do not know which of the two is a stronger nucleophile, I will displace $$\ce{I-}$$ and form $$\ce{alkyl-SH}$$. But definitely only one of the reactions shall occur.

So, my question is that is there an order of strength of nucleophilicity (like a metal reactivity series)? I am preparing for JEE Advanced 2015 and(college entrance exam in India), so I am expecting answers which within thisits scope of knowledge.

For eg. in Finklestein reaction, $$\ce{NaI}$$ (reagent) taken in acetone(solvent) displaces $$\ce{SH-}$$ ion from alkyl group via SN2 mechanism to form alkyl iodide. But in a separate question we may be asked to write the product formed when $$\ce{NaSH}$$ reacts with alkyl iodide in the presence of acetone. Since I do not know which of the two is a stronger nucleophile, I will displace $$\ce{I-}$$ and form $$\ce{alkyl-SH}$$. But definitely only one of the reactions shall occur. So my question is that is there an order of strength of nucleophilicity (like a metal reactivity series)? I am preparing for JEE Advanced 2015 and am expecting answers which within this scope of knowledge.

How to determine order of nucleophilicity among commonly used nucleophiles? For example, in Finklestein reaction, $$\ce{NaI}$$ (reagent) - taken in acetone  (solvent) - displaces $$\ce{SH-}$$ ion from alkyl group via SN2 mechanism to form an alkyl iodide. But in a separate question we may be asked to write the product formed when $$\ce{NaSH}$$ reacts with an alkyl iodide in the presence of acetone. Since I do not know which of the two is a stronger nucleophile, I will displace $$\ce{I-}$$ and form $$\ce{alkyl-SH}$$. But definitely only one of the reactions shall occur.

So, my question is that is there an order of strength of nucleophilicity (like a metal reactivity series)? I am preparing for JEE Advanced 2015 (college entrance exam in India), so I am expecting answers within its scope.

2 added 32 characters in body

For eg. Inin Finklestein reaction, NaI$$\ce{NaI}$$ (reagent) taken in acetone(solvent) displaces SH(-)$$\ce{SH-}$$ ion from alkyl group via SN2 mechanism to form alkyl iodide. But in a separate question we may be asked to write the product formed when NaSH$$\ce{NaSH}$$ reacts with alkyl iodide in the presence of acetone. Since I do not know which of the two is a stronger nucleophile, I will displace I(-)$$\ce{I-}$$ and form alkyl-SH$$\ce{alkyl-SH}$$. But definitely only one of the reactions shall occur. So my question is that is there an order of strength of nucleophilicity (like a metal reactivity series)? I am preparing for JEE Advanced 2015 and am expecting answers which within this scope of knowledge.

For eg. In Finklestein reaction, NaI(reagent) taken in acetone(solvent) displaces SH(-) ion from alkyl group via SN2 mechanism to form alkyl iodide. But in a separate question we may be asked to write the product formed when NaSH reacts with alkyl iodide in the presence of acetone. Since I do not know which of the two is a stronger nucleophile, I will displace I(-) and form alkyl-SH. But definitely only one of the reactions shall occur. So my question is that is there an order of strength of nucleophilicity (like a metal reactivity series)? I am preparing for JEE Advanced 2015 and am expecting answers which within this scope of knowledge.

For eg. in Finklestein reaction, $$\ce{NaI}$$ (reagent) taken in acetone(solvent) displaces $$\ce{SH-}$$ ion from alkyl group via SN2 mechanism to form alkyl iodide. But in a separate question we may be asked to write the product formed when $$\ce{NaSH}$$ reacts with alkyl iodide in the presence of acetone. Since I do not know which of the two is a stronger nucleophile, I will displace $$\ce{I-}$$ and form $$\ce{alkyl-SH}$$. But definitely only one of the reactions shall occur. So my question is that is there an order of strength of nucleophilicity (like a metal reactivity series)? I am preparing for JEE Advanced 2015 and am expecting answers which within this scope of knowledge.