Author: Anonymous

1.10 The mass (in grams) of 7,25 dm3 of O2 gas at STP is:   (2)

QUESTION 2 Water has a high heat of vaporisation value of 40,7 kJ.mol-1. 2.1 Identify the attribute of water causing this high heat of vaporisation. (1) 2.2 Discuss the advantage of the resistance mentioned in QUESTION 2.1  for our planet and all living organisms. (3) A water molecule is polar while a carbon dioxide molecule is non- polar. 2.3 What is the difference between a polar and a non- polar molecule? (2) 2.4 What is the name of the shape given to the water molecule? (1) 2.5 Use electronegativity difference to determine the type of bond present in the carbon dioxide molecule. (2) 2.6 What is the easiest way to increase the amount of kinetic energy in a system? (2) 2.7 How does the density of a solid compare to the density of a liquid? Explain your answer in terms of intermolecular forces. (3) 2.8 What are meant by the terms ‘thermal expansion’ and ‘thermal conductivity’? (4) 2.9 What happens to the density of liquid water as the temperature rises? Briefly explain your answer. (3)           [21]

1.7 Sodium chloride (NaCl) is a solid which is soluble in water. Which one of the following describes the intermolecular forces that exist between sodium chloride and water in solution?         (2)

1.6 The bond in the H2O molecule is described as polar covalent because:   (2)

QUESTION 3 Consider a hydronium ion (H3O+). 3.1 Draw the Lewis structure of H3O+. (3) 3.2 Identify the shape of H3O+. (1) 3.3 Use the VSEPR to explain the shape mentioned in QUESTION 3.2 (2) 3.4 Explain what is meant by a dative covalent bond. (2)           [8]

1.2 Choose the molecule with a trigonal pyramidal shape: (2)

1.3 Which of the following are the types of forces of attraction between non-polar molecules?   (2)

TOTAL FOR PAPER: [125]

1.8 Consider the balanced chemical equation: 2H2(g) + O2(g)

QUESTION 8 An essential amino acid Lysine has a molar mass of 146,19 g.mol-1and a percentage composition as follows: 49,29 % C; 9,66 % H; 19,16 % N and21,89% O. 8.1 Define the term empirical formula (2) 8.2 Determine the molecular formula (8)           [10]