State VSEPR theory and predict the shapes of PCl₅, CO₂, H₂O, XeF₆, and NO₂⁺. Give the name and structure of the transition metal complex [CuCl₄]²⁻.

Here is the answer to question 6:

6a. State VSEPR theory and predict the shapes of the following:

• VSEPR Theory (Valence Shell Electron Pair Repulsion Theory) states that electron pairs (both bonding and lone pairs) around a central atom will arrange themselves as far apart as possible to minimize repulsion, thereby determining the molecular geometry.

  • i. PCl₅

    • Central atom: P
    • Number of electron domains: 5 bonding pairs, 0 lone pairs
    • Shape: Trigonal bipyramidal

  • ii. CO₂

    • Central atom: C
    • Number of electron domains: 2 bonding pairs (double bonds count as one domain), 0 lone pairs
    • Shape: Linear

  • iii. H₂O

    • Central atom: O
    • Number of electron domains: 2 bonding pairs, 2 lone pairs
    • Shape: Bent (or V-shaped)

  • iv. XeF₆

    • Central atom: Xe
    • Number of electron domains: 6 bonding pairs, 1 lone pair
    • Shape: Distorted octahedral

  • v. NO₂⁺

    • Central atom: N
    • Number of electron domains: 2 bonding pairs (double bonds count as one domain), 0 lone pairs
    • Shape: Linear

6b. Give the name and structure of the following transition metal complexes:

• i) [CuCl₄]²⁻

  • Name: Tetrachlorocuprate(II) ion
  • Structure: Tetrahedral

• ii) [Ag(NH₃)₂]⁺

  • Name: Diamminesilver(I) ion
  • Structure: Linear

6c. Give reasons for the following facts about halogens:

• i) halogens belong to group seven in the periodic table.

  • Reason: Halogens are in Group 17 (formerly Group VIIA) because they all possess seven valence electrons in their outermost electron shell.

• ii) halogens are the most reactive non-metal known.

  • Reason: Halogens are highly reactive non-metals because they have a strong tendency to gain one electron to achieve a stable noble gas electron configuration (an octet). This is due to their high electronegativity and electron affinity.

6d. How many atoms are there in 6g of carbon?