Sure, let's go through the given question part by part.
### Naming Compounds Using IUPAC System
#### (i) [tex]\(CCl_4\)[/tex]
The compound [tex]\(CCl_4\)[/tex] consists of one carbon atom and four chlorine atoms. According to the IUPAC naming system, the compound is named as follows:
- The central atom is carbon, and the substituents are chlorine atoms.
- The prefix "tetra-" is used to indicate the four chlorine atoms.
Thus, the IUPAC name for [tex]\(CCl_4\)[/tex] is tetrachloromethane. However, it is also commonly known as "carbon tetrachloride".
#### (ii) [tex]\(HOCl\)[/tex]
The compound [tex]\(HOCl\)[/tex] consists of a hydroxyl group (OH) and a chlorine atom. According to the IUPAC naming system:
- The compound is an oxoacid of chlorine (a compound consisting of hydrogen, oxygen, and chlorine).
- The name is derived from "hypo-" indicating one oxygen atom less than the common oxoacids of chlorine and "-ous" indicating the presence of oxygen.
Thus, the IUPAC name for [tex]\(HOCl\)[/tex] is hypochlorous acid.
### Explanation for the Melting Point of Oxides
#### (a) Melting Points Discussion
- We are given the melting points and ionic radii of the oxides of elements [tex]\(W\)[/tex] and [tex]\(Z\)[/tex].
- [tex]\(W\)[/tex]: Melting point of -117°C, Ionic radius = 0.418 nm
- [tex]\(Z\)[/tex]: Melting point of 1399°C, Ionic radius = 0.489 nm
Why is the melting point of the oxide of [tex]\(W\)[/tex] lower than that of the oxide of [tex]\(Z\)[/tex]?
Melting points of oxides generally depend on the type of bonding and the strength of the lattice structure of the oxide.
- Ionic Bonding: Oxides formed from metals typically exhibit ionic bonding. The strength of ionic bonds is influenced by the charge density of the ions.
- Covalent Bonding: Oxides formed from non-metals typically exhibit covalent bonding, which can have a varying impact on melting point based on molecular interactions.
Comparing [tex]\(W\)[/tex] and [tex]\(Z\)[/tex]:
- Element [tex]\(W\)[/tex]: The given melting point (-117°C) is significantly low, which suggests weaker intermolecular or ionic interactions. This lower melting point hints that the oxide of [tex]\(W\)[/tex] possibly has weaker van der Waals forces due to a smaller lattice energy.
- Element [tex]\(Z\)[/tex]: The high melting point (1399°C) suggests a much stronger ionic or covalent network. This implies a stronger bonding and higher lattice energy within the oxide of [tex]\(Z\)[/tex].
The larger atomic radii and heavier atomic mass lead to weaker attractions between the oxide particles in [tex]\(W\)[/tex], thus resulting in a lower melting point. The stronger bonds in [tex]\(Z\)[/tex] lead to a larger amount of energy required to break the lattice, resulting in a higher melting point.
So, the melting point of the oxide of [tex]\(W\)[/tex] is lower than that of [tex]\(Z\)[/tex] primarily due to the weaker intermolecular forces or reduced bond strength in the oxide of [tex]\(W\)[/tex].
