2. for one of the following molecules/ions:\ni) draw the lewis structure\nii) predict the electron group…

2. for one of the following molecules/ions:\ni) draw the lewis structure\nii) predict the electron group arrangement and shape using vsepr.\niii) indicate and justify the overall polarity of the molecule/ion\niv) list the intermolecular forces (imf’s) that would be present\na) pcl₅ or b) no₃⁻
Answer
Explanation:
Step1: Determine valence electrons for PCl₅
Phosphorus (P) has 5 valence electrons and each chlorine (Cl) has 7 valence electrons. For PCl₅, total valence electrons = 5+(5×7)=40.
Step2: Draw Lewis structure for PCl₅
P is the central atom. Connect P to 5 Cl atoms with single - bonds. Each Cl has 3 lone - pairs to complete its octet.
Step3: Predict electron - group arrangement and shape using VSEPR
The central P atom has 5 bonding pairs and 0 lone - pairs. The electron - group arrangement is trigonal bipyramidal and the molecular shape is also trigonal bipyramidal.
Step4: Determine polarity of PCl₅
The P - Cl bonds are polar due to electronegativity difference. But the trigonal bipyramidal geometry of PCl₅ is symmetric, so the bond dipoles cancel out and the molecule is non - polar.
Step5: Identify intermolecular forces
Since PCl₅ is non - polar, the only intermolecular forces present are London dispersion forces.
Answer:
i) Lewis structure: P is in the center with 5 single bonds to Cl atoms, and each Cl has 3 lone - pairs. ii) Electron - group arrangement: trigonal bipyramidal; Molecular shape: trigonal bipyramidal iii) Polarity: Non - polar. Justification: Symmetric trigonal bipyramidal geometry causes bond dipoles to cancel. iv) Intermolecular forces: London dispersion forces