Question

½ H2(g) + ½ I2(g) HI(g), H = +6.2 kcal/mole what reaction is this

Answer 1

Endothermic

Answer 2

as well as addition reaction

Answer 3

Molecular Hydrogen H2 and Iodine forms Hydrogen ionide.
Reaction is endothermic because H > 0, It needs energy to happen.
Reaction happens in high temperature, because iodine gas.