1-heptyne is a compound which consists of 7 carbons with a triple bond between the first and second C. When this reacts with HX (X being a halogen), it follows the Markovnikov Rule. This means that the hydrogen bonds with the carbon containing a lot of bonding hydrogen atoms. At the same time, the halogen bonds with the carbon with the least H atoms.
Thus, the product would be
2-bromo-1-heptene
