Question

In reaction between chlorine and HBr a transformation of HBr takes place. What kind of transformation is that?

Answer 1

That transformation that takes place for this case is substitution.

The fact is that both chlorine and bromine are halogens and the reactivity of halogens increases down the group. This is to say that chlorine is more reactive than bromine hence chlorine will displace bromine from hydrogen bromide.

So the net effect is that hydrogen chloride will produced in stead.

Answer 2

Hydrogen bromide reacts with chlorine to form hydrogen chloride and bromine. This is actually a substitution reaction as they both are halogens.

Chlorine is more reactive than bromine as it is present above the bromine in periodic table and the reactivity of halogens decreases down the group hence chlorine can replace bromine and can be converted to hydrogen chloride in the reaction.