This Study Mind Tutorial covers the following specification points:

Edexcel: 2.16(i-iii), 2.17, 2.18(i,ii), 2.19, 2.20

2.16. understand the nature of intermolecular forces resulting from the following interactions:

(i) London forces (instantaneous dipole – induced dipole)

(ii) permanent dipoles

(iii) hydrogen bonds

2.17. understand the interactions in molecules, such as H₂O, liquid NH₃ and liquid HF, which give rise to hydrogen bonding

2.18. understand the following anomalous properties of water resulting from hydrogen bonding:

(i) its relatively high melting temperature and boiling temperature

(ii) the density of ice compared to that of water

2.19. be able to predict the presence of hydrogen bonding in molecules analogous to those mentioned above

2.20. understand, in terms of intermolecular forces, physical properties shown by materials, including:

(i) the trends in boiling temperatures of alkanes with increasing chain length

(ii) the effect of branching in the carbon chain on the boiling temperatures of alkanes

(iii) the relatively low volatility (higher boiling temperatures) of alcohols compared to alkanes with a similar number of electrons

(iv) the trends in boiling temperatures of the hydrogen halides, HF to HI