Question

Arrange the following in order of increasing melting points.

CsCl, BaCl_2, diamond (C), H_2, HF
a. H_2 < HF < BaCl_2 < CsCl < diamond
b. HF < H2 < CsCl < BaCl_2 < diamond
c. H_2 < HF < CsCl < BaCl2 < diamond
d. H_2 < HF < diamond < CsCl < BaCl_2
e. HF < H_2 < diamond < CsCl < BaCl_2

Answer 1

The order of increasing melting points is H₂ < HF < CsCl < BaCl₂ < diamond.

Step-by-step explanation:

The melting points of substances depend on the type of bonding present in the compounds.

First, let's classify the given substances:

• CsCl (Cesium Chloride) - Ionic
• BaCl₂(Barium Chloride) - Ionic
• Diamond (C) - Covalent
• H₂ (Hydrogen gas) - Covalent
• HF (Hydrogen Fluoride) - Covalent

Ionic compounds tend to have higher melting points compared to covalent compounds. Within the covalent compounds, the larger the molecule, the higher the melting point.

So, the correct order of increasing melting points is H₂ < HF < CsCl < BaCl₂ < diamond.

Answer 2

The order of increasing melting points for the given compounds is H2 < HF < BaCl2 < CsCl < diamond.

Step-by-step explanation:

The melting point of a substance is influenced by its intermolecular forces. Generally, substances with stronger intermolecular forces have higher melting points. Ionic compounds have strong electrostatic forces between oppositely charged ions, covalent compounds have strong covalent bonds between atoms, molecular compounds have weak intermolecular forces between molecules, and metallic compounds have a structure of positive ions surrounded by a sea of delocalized electrons.

Using this information, we can determine the order of increasing melting points:

1. H2 and HF both have weak intermolecular forces and will have lower melting points compared to the other compounds.
2. Among CsCl, BaCl2, and diamond (C), CsCl is an ionic compound with strong electrostatic forces and will have the highest melting point.
3. BaCl2 is also an ionic compound, but it has a higher melting point compared to diamond (C) because of the larger ions and stronger electrostatic forces.
4. Diamond (C) has a strong covalent bond between carbon atoms, resulting in a high melting point.

Based on this, the correct order of increasing melting points is option

a. H2< HF < BaCl2 < CsCl < diamond.