Organic Chemistry: Which would be expected to have the higher reaction rate?

[grindtime1]

15% NaI reaction with 1 M bromobutane vs 15% NaI reacting with 2 M bromobutane


7.5% NaI reacting with 1M bromobutane vs 15% NaI reacting with 1 M Bromobutane.

---

Members don't see this ad.

 

[SolidWater]

Seems logical that in the first one the 2M bromobutane would have a higher reaction rate...there's more bromobutane in the solution to react with the NaI....unless this being an SN2 reaction has a different impact on concentrations?

Same for the second set IMO: 15% NaI...there's simply more of it.

 

[mmmcdowe]

15% NaI reaction with 1 M bromobutane vs 15% NaI reacting with 2 M bromobutane


7.5% NaI reacting with 1M bromobutane vs 15% NaI reacting with 1 M Bromobutane.

First decide whether or not these are SN1 or SN2 Reactions. Identify the nucleophile then ask, is the leaving group on a primary secondary or tertiary carbon. Choose SN1 vs SN2 vs E1 vs E2 appropriately based on nucleophile strength, feasibility, etc.

having found the type of reaction, then ask yourself what the rate is. The rate will either be
k(nucleophile)(substrate) or k(substrate). Since you already identified which is the nucleophile and which is the substrate, the rest should be cake.

In this case, unless I am missing something, I don't see why this reaction would go forward. The nucleophile is weaker than the leaving group. I guess it depends on where the bromine is on the carbon chain and what solution you are in to see how much iodobutane would be formed, but I would expect bromobutane to be the major product in the end unless this is a SN1 problem with a extremely high activation energy of the rate limiting step.

 

[JJMrK]

Threads created for the purpose of soliciting homework help are not allowed on SDN.