Does the solvent determine whether an alkyl halide will undergo an SN1 or an SN2 reaction?

Friedel Craft alkylation (or acylation) is by definition an electrophilic aromatic substitution whereby an alkyl or acyl group is substituted for a hydrogen atom on an aromatic ring. So if...

The bond strength of a $2""^@$ alkyl halide must be comparable to a $1""^@$ alkyl halide. Enthalpy is thus not really a determinant. In terms of kinetics, the $1""^@$ halide...

You could write whole chapters in an organic text to answer this question. And of course what follows is merely a guide to further reading. We know that $S_(N)1$ reactions...$"substitution...

In a $S_n1$ reaction the reaction rate does only depend on the concentration of the substrate. Mening that you can add all the nucleophile you wan't but the reaction wont...

1-more stearic hindrance, more chance to give SN1 Rn. vice versa 2-more hyperconjugation capability of a substrate, more stable will be the carbocation ultimately more chance to give SN1 Rn....

Water is a weak nucleophile so it would favor SN1. We know that weak nucleophiles doesn't have any negative charge (i.e. -OH, Iodine).

The clearest difference is in their names! SN1 reactions are unimolecular, stepwise mechanisms, where, $"R" = k["LG"^(-)]$ SN2 reactions are bimolecular, concerted mechanisms, where, $"R" = k["LG"^-]["Nu"]$ These reactions are...

Now of course $S_N1$ and $S_N2$ reactions are DISSOCIATIVE (i.e. bond-breaking), and ASSOCIATIVE (bond-making) respectively to a first approximation. Associative mechanisms are largely restricted to methyl, primary, and more rarely,...

The point is that YOU DON'T KNOW. And for this we apply $"a posteriori"$ reasoning, argument AFTER the fact, rather than $"a priori"$ reasoning, argument BEFORE the fact. Mix...

For nucleophilic substitutions, SN1 and SN2 are equally important, however, for the $beta$-elimination, E2 is much more common and useful than E1.