Which statement correctly describes what happens when a sample of liquid propanone, CH3COCH3\text{CH}_3\text{COCH}_3CH3COCH3, is vaporised at its boiling point?
Covalent C−H\text{C}-\text{H}C−H and C=O\text{C}=\text{O}C=O bonds within the propanone molecules are broken.
Hydrogen bonds and permanent dipole-dipole forces between the molecules are overcome.
Permanent dipole-dipole forces and London forces between the molecules are overcome.
The enthalpy of the substance decreases as the process is exothermic.
54 exam-style questions on AQA A Level Chemistry Bonding, covering Ionic bonding, Nature of covalent and dative covalent bonds, Metallic bonding, Bonding and physical properties, Shapes of simple molecules and ions, Bond polarity, and Forces between molecules. Each one has a worked solution and a mark scheme showing where the marks go.