Bonding and Intermolecular Forces – Practice Questions

Simple Molecules

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

Intermolecular Forces

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.

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