Reactions Of Halogenoalkanes 1 Chemsheets Answers Exclusive May 2026

Potassium cyanide (KCN) dissolved in ethanol/water mixture. The Product: Nitrile (alkanenitrile). The Mechanism: Nucleophilic substitution (typically SN2).

Add ethanol (to dissolve the organic halide), then aqueous silver nitrate. Warm gently. reactions of halogenoalkanes 1 chemsheets answers exclusive

This is a slower, less vigorous reaction than with OH⁻. Potassium cyanide (KCN) dissolved in ethanol/water mixture

“1-bromopropane is heated with NaOH(aq) and separately with NaOH in ethanol. State the major product in each case and explain.” Add ethanol (to dissolve the organic halide), then

Both reactions start with the same halogenoalkane and a base/nucleophile (e.g., OH⁻). The outcome depends on:

| Factor | Favors Substitution (SN2 or SN1) | Favors Elimination (E2 or E1) | |---|---|---| | | Lower temp (25°C) | Higher temp (>60°C, reflux) | | Nucleophile/Base | Strong nucleophile, weak bulky base (e.g., OH⁻, CN⁻, NH₃) | Strong, bulky base (e.g., KOH in ethanol , not water; or tert-butoxide) | | Halogenoalkane structure | Primary (SN2 only); Tertiary (SN1) | Tertiary (E1 or E2); primary needs strong bulky base (E2) | | Solvent | Polar protic (water, alcohols) for SN1; Polar aprotic (DMSO, acetone) for SN2 | Polar protic also works; non-polar favors E2 |

| Halogenoalkane | Precipitate Color | Rate of Precipitation | Bond Enthalpy (C-X) | |---|---|---|---| | Fluoroalkane | No precipitate (AgF soluble) | Very slow (usually not seen) | Very high (484 kJ/mol) | | Chloroalkane | White (AgCl) | Slow (minutes, needs warming) | 338 kJ/mol | | Bromoalkane | Cream (AgBr) | Faster (seconds to minutes) | 276 kJ/mol | | Iodoalkane | Yellow (AgI) | Instant (room temperature) | 238 kJ/mol |