Which conditions favour substitution?

• Hot concentrated strong base
• Lower temperature with a good nucleophile that is a weak base, in dilute solution
• Bulky base with a crowded substrate

What forms when hydroxide acts as a base toward a haloalkane?

• An alcohol by substitution
• An alkene by elimination, with a new double bond
• An amine

Which conditions favour elimination?

• Dilute cool weak base
• Polar solvent with a weak base
• Strong base, high temperature and concentrated solution

What does it mean to call hydroxide both a nucleophile and a base?

• It can attack carbon to substitute or grab a hydrogen to eliminate
• It can only ever substitute
• It changes element between reactions

What changes between hydrolysing bromopropane and making propene from it?

• The halogen changes from bromine to chlorine
• Dilute cool aqueous conditions give propanol while hot concentrated conditions give propene
• Propene needs a different halogen entirely

A bulky base favours substitution because it reaches carbon easily.

Circle one:   True   False

A student draws elimination with hydroxide bonding to carbon. What is the error?

• That arrow shows substitution, while elimination needs hydroxide pulling a hydrogen
• Hydroxide can never touch a haloalkane
• Elimination has no arrows at all

Two alkenes can form from one haloalkane. Which is the major product?

• The least substituted alkene
• Always the cis version regardless of substitution
• The more substituted alkene, with more carbon groups on the double bond