Why are SN2 reactions better in aprotic? (Poor solvation of the nucleophile favors SN2, while poor solvation of the leaving group disfavors SN1. - GS). Are both Sn2 and Sn1 reactions better in polar vs nonpolar? (Yes. Polarity helps formation of a carbocation (for SN1) and helps to dissolve the nucleophile (for both SN2 and SN1). - GS).

Can we please re-discuss why protic solvents cause products to form faster and why they are more favored than aprotic solvents in SN1 reactions? (Because protic solvents solvate anions in addition to carbocations. - GS).

Can you explain conformation vs configuration?  (Configuration can be changed only by breaking chemical bonds. Conformation changes when a molecule adopts a different shape, without breaking bonds. - GS). So E/Z would be considered a configuration? (Yes. - GS). Okay, thanks!

What is the difference between NaNh2 and Na, NH3 (This first reagent is a strong base, the second one is a strong reducing agent. - GS).

Why does halogenation of alkynes make stereoselectivity of addition unpredictable? (Because the 3-membered bromonium responsible for anti-stereoselectivity, is unstable (too strained) - GS).

What are other ways to create an acetylenide other than using NaNH2? (Grignard reagents, alkyllithium compounds, such as Butyl lithium - GS).