|A) Cl2(g) + 2NaF(aq)--> F2(g) + 2NaCl(aq)||B) I2(s) + 2NaF(aq)--> F2(g) + 2NaI(aq)|
|C) Cl2(g) + 2NaBr(aq)-->Br2(l) + 2NaCl(aq)||D) I2(s) + 2NaBr(aq)--> Br2(l) + 2NaI(aq)|
In this chemical reaction chlorine change oxidation number from 0 to -1 (reduction) and bromine change oxidation number from -1 to 0 (oxidation).
Chlorine is stronger oxidation reagent than bromine.
In VIIA or group 17 (halogen elements) there are six elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At) and tennessin(Ts).
They have high electronegativity because they have seven valence electrons in their outermost energy level, so they can gain an electron to have the octet rule.
Going down in the group, element are weaker oxidazing reagent and less reactive.