In general, alkenes are more reactive to electrophiles than their corresponding alkynes. However, this reactivity difference is much greater and more evident in the addition of HBr as compared to the addition of Br₂. Explain why this is the case. 

Which of the below-given alkenes would be protonated faster?

Determine the major product when the Br₂ (2 mol)/CH₂Cl₂ reagent reacts with 2-pentyne.

Determine the major product formed in a reaction between pent-2-yne and 1 eq. of Br  ₂ in CH₂Cl₂.

Determine the identity of products obtained in the reaction of but-1-yne with each of the reagents shown below.
(i) H₂, Pd/BaSO₄ catalyst, quinoline
(ii) Br₂ (1 equivalent)
(iii) Br₂ (2 equivalents)

At which carbon would an electrophile attach in hex-1-en-5-yne? Provide a reason.

Provide an alkene that will only generate the given alkyl halide after reaction with a suitable hydrohalic acid. Disregard stereochemistry.

Determine the major product formed when each compound below reacts with HCl.

Draw the mechanism of the reaction below. (Ignore stereochemistry)

Determine the product(s) formed when the following molecule reacts with H₂SO₄ and H₂O.

Draw the mechanism of the reaction below. Take note of rearrangements.

Give the stereoisomers produced by the reaction shown below.

Determine the product(s) of the oxymercuration–demercuration reaction of the following alkene:

What are the product(s) formed when the following compound reacts with (1) Hg(OAc) ₂, H₂O, and then with (2) NaBH₄?