Predict which of the following pair will have the higher melting point and indicate why: KBr, Br2.

a. KBr: strong hydrogen bonding forces
b. KBr: strong ion-ion forces
c. KBr: strong dipole-dipole forces
d. Br2: strong LDF
e. Br2: strong covalent-network forces

KBr: strong ion-ion forces

Explanation:

Ionic compounds are non-molecular species. During melting they require a lot of energy input so that the strong ionic bonds that constitute the electrostatic lattice be disrupted. It thus requires very high temperatures. This is indicative of a very strong ion-ion electrostatic interaction which is typical of ionic bonds and results in high melting points of ionic solids.

Hence, the process of melting an ionic solid needs the addition of a large amount of energy in order to break all of the ionic bonds in the crystal.

On the other hand, Br2 is a covalent molecular specie. Most covalent compound have low melting points since their molecules are mostly held together only by weak van der waals forces.

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.