Question

melting point order of NaF, NaCl, NaBr. with reason

Answer 1

Answer:

NaBr<NaCl<NaF

Explain:

We know that as we move down the group, the size of the atom increases, and hence the electronegativity of the atom decreases. Thus for group 17 elements, fluorine will be the most electronegative while bromine will be the least electronegative. As a result, electrostatic attraction between the cation and anion will be maximum in NaF and minimum in Nabr. So, the amount of energy required to pull the negative and the positive ions apart would be maximum in NaF. As a result, the increasing order of melting point of sodium halides is Nabr