Question 7 1 pts The central atom in ICI, ion has [Select] bonding groups of electrons and [Select] *lone pairs of electrons. The electron geometry of the ion is [Select] and the molecular geometry is [Select] ▼
The Correct Answer and Explanation is :
The central atom in the ICl₄⁻ ion has five bonding groups of electrons and one lone pair of electrons. The electron geometry of the ion is octahedral, and the molecular geometry is square pyramidal.
Explanation:
- Central Atom: The central atom in ICl₄⁻ is iodine (I), which belongs to Group 17 of the periodic table. In the ion ICl₄⁻, iodine forms bonds with four chlorine (Cl) atoms and carries a negative charge. We can deduce the bonding and lone pairs from its electron configuration.
- Bonding Groups and Lone Pairs: In ICl₄⁻, iodine is surrounded by four chlorine atoms, and there is one lone pair of electrons on the iodine atom. Since iodine is in Group 17, it can form multiple bonds, and its valence shell can accommodate more than eight electrons. The four bonding groups come from the four I-Cl bonds, and the lone pair corresponds to the single lone pair of electrons that iodine retains.
- Electron Geometry: The electron geometry considers the total number of electron groups around the central atom, which includes both bonding pairs and lone pairs. In the case of ICl₄⁻, there are a total of five electron groups: four bonding groups (from the I-Cl bonds) and one lone pair. The arrangement of these five electron groups forms an octahedral geometry.
- Molecular Geometry: The molecular geometry focuses on the positions of the atoms, excluding lone pairs. Since one of the positions in the octahedral geometry is occupied by a lone pair, the geometry of the ion is distorted into a square pyramidal shape, where the iodine atom is at the center, and the four chlorine atoms are positioned at the corners of a square, with the lone pair affecting the geometry slightly.
In summary, the ICl₄⁻ ion has five electron groups (four bonding groups and one lone pair), resulting in an electron geometry of octahedral and a molecular geometry of square pyramidal.