For the reaction of 1-bromobutane with sodium azide (all at the same concentration and temperature), the rate is highest in

Aacetonitrile
Bmethanol
Cethanol
Dwater

Answer: A

Acetonitrile is a polar aprotic solvent: it dissolves the salt (it solvates the sodium ion) but does not hydrogen bond to azide, leaving it highly nucleophilic. Methanol, ethanol and water all hydrogen bond to the anion and slow the reaction.

Practice Organic Reaction Mechanisms III: Nucleophilic Substitution More on SN1 vs SN2: substrate, nucleophile, solvent, leaving group

Previous questionNext question

More questions on SN1 vs SN2: substrate, nucleophile, solvent, leaving group

Towards CH3I in the corresponding alcohol, ethoxide is a better nucleophile than tert-butoxide even though tert-butoxide is the stronger bas... JEE Main level
The reaction CH3CH2Br + N3- -> CH3CH2N3 + Br- is run at a given temperature. Which changes will increase the rate constant of this SN2 react... JEE Main level
Assertion (A): The reaction of CH3CH2Br with NaN3 is much faster in DMF than in methanol. Reason (R): DMF is a hydrogen-bond donor and stabi... JEE Main level
Two sequences are carried out on bromoethane. Sequence I: KCN in aqueous ethanol, then boiling with dilute HCl. Sequence II: AgCN in ethanol... JEE Advanced level
Triethylamine reacts with iodoethane to give tetraethylammonium iodide, an SN2 reaction in which neutral reactants form an ion pair (the Men... JEE Advanced level
Sodium 2-naphthoxide is treated with benzyl bromide in four different solvents. In which solvent is the proportion of ring (C-) alkylation, ... JEE Advanced level