Give the structure of the product you would expect from the reaction (if any) of 2-butyne with one molar equivalent of hbr. if there is no product, simply draw the reactant, 2-butyne. note: all structures should be drawn with no bonds between carbon and hydrogen.

(Z)-2-bromo-2-butene is produced here.

Explanation:

Reaction of 2-butyne with one equivalent of HBr yields (Z)-2-bromo-2-butene.

In the first step, protonation of triple bond produces a carbocation with a double bond. Two methyl groups present in carbocation remain in opposite side to avoid steric interaction.

In the second step, a bromide ion gives nucleophilic addition reaction with carbocation to give (Z)-2-bromo-2-butene.

Full reaction mechanism has been shown below.

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."

its first and third is your answer i did the qustion the fourth isnt right