1: Draw dot-cross diagrams for
i) PH3, ii) CS2, iii) BF3, iv) SCl2
2: Draw a dot-cross diagram for the ion H3O+
3: Ozone and sulphur trioxide also have dative bonds. Draw a dot-cross diagram for
i) O3, ii) SO3. (Note that sulphur in SO3 has an expanded octet)
4: Predict the shapes and bond angles in:
i) sulphur dichloride (SCl2) ii) silane (SiH4) iii) carbon disulphide (CS2)
iv) sulphur trioxide (SO3) v) ozone
Giant Ionic Structures
5: Draw dot-cross diagrams for
i) lithium oxide ii) aluminium fluoride
6: Arrange the following groups of substances in order, highest boiling point first
i) Ne, He, Ar
ii) chloromethane, fluoromethane, bromomethane
7: Consider the series of molecules CH4, CH3Cl, CH2Cl2, CHCl3 and CCl4
i) Which of these contains polar bonds ?
ii) Which of these molecules is polar ?
8: Explain why the ammonium ion contains polar bonds but has no overall dipole
9: Arrange the following groups of substances in order, highest boiling point first.
i) butane ii) methylpropane iii) 1-chlorobutane iv) 2-chloro methylpropane
10: What is the main type of interaction between molecules in:
i) butanone ii) pentene
11: Explain why pentane has a b.p. of 36°C while 2-methylbutane has a b.p. of 28°C
12: Draw a diagram to illustrate the hydrogen bonding in ammonia
13: Place the following molecules into order of increasing boiling point:
CH3OH, CH4, CH2O
14: Compare the intermolecular forces in ammonia, NH3, and hydrazine, N2H4, and suggest which will have the highest boiling point.