A haloalkane is warmed with sodium hydroxide. Which conditions give an alcohol rather than an alkene?

1. The same two reactants can follow two different routes, so the conditions decide the product. 2. Substitution swaps the halogen atom for a hydroxyl group and gives an alcohol. 3. Elimination pulls off the halogen atom together with a hydrogen atom and gives an alkene. 4. Substitution needs a dilute solution of a strong base, dissolved in water, at about room temperature. 5. Elimination needs a concentrated strong base dissolved in pure ethanol, heated under reflux. 6. So a dilute base in water is what steers the reaction towards the alcohol. 7. The strong base in ethanol option is precisely the trap, because those are the elimination conditions. 8. No solvent at all leaves nothing for the base to dissolve in, and light drives the substitution of alkanes rather than of haloalkanes. _Source: Siyavula Physical Sciences Grade 12 (Everything Science, CC BY 4.0), Chapter 4: Organic molecules_