Chemical Bonding and Molecular Structure — Practice

Question 1

Determine the hybridisation and shape of SF4.

Accepted Answer

S has 6 valence electrons: 4 bond pairs + 1 lone pair = 5 electron pairs, so sp3d hybridisation. The lone pair occupies an equatorial position, giving a see-saw shape (not trigonal bipyramidal).

Question 2

Calculate the bond order of O2 2- (peroxide ion) and predict its magnetic behaviour.

Accepted Answer

O2 2- has 18 electrons. Bond order = (10 - 8)/2 = 1. All electrons are paired, so it is diamagnetic.

Question 3

Why is H2O bent but CO2 linear?

Accepted Answer

In H2O, oxygen has 2 bond pairs and 2 lone pairs (sp3), and the lone pairs push the bonds together giving a bent shape. In CO2, carbon has 2 double bonds and no lone pairs (sp), giving a linear shape.

Question 4

Explain why O2 is paramagnetic using molecular orbital theory.

Accepted Answer

O2 has 16 electrons. The last two occupy the two degenerate pi*2p antibonding orbitals singly with parallel spins (Hund's rule). These two unpaired electrons make O2 paramagnetic -- a result that Lewis structures cannot explain but MO theory predicts.

Question 5

Why does water have a higher boiling point than H2S?

Accepted Answer

Water forms strong intermolecular hydrogen bonds (O-H...O) because oxygen is small and highly electronegative. H2S cannot form effective hydrogen bonds, so it has a much lower boiling point despite being in the same group.

Practice — Chemical Bonding and Molecular Structure

Sign in to save attempts to your dashboard and track your accuracy over time

Find a verified tutor

Join a live course

Browse coaching centres

About

Categories

Support

Documentation

Get Study Tips & Updates

Download Our App

Download for iOS

Download for Android

Popular Cities