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Question 3   3.1 Look at the four different molecules shown in the diagram linked below and answer the questions that follow.   Right click on the button below to open the image in a new tab     3.1.1 Which one of the four molecules can exhibit hydrogen bonding among other molecules of the same type? Give the chemical formula. (1) 3.1.2 Give the IUPAC name for the molecule you chose in 3.1.1. (1) 3.1.3 Give the common name for the molecule you chose in 3.1.1. (1) 3.2 Explain why the molecule you chose in question 3.1.1 will form hydrogen bonds with other molecules exactly like it while the other molecules will not. (3) 3.3 Name the type of intermolecular force that the other three molecules in the diagram will undergo with other molecules of their own type. Give a reason. (3) 3.4 Which of the four compounds represented by the molecules in the diagram will have the highest boiling point? Explain your answer. (3) 3.5 Draw a diagram of the intermolecular forces between three H2S molecules, indicating polarities. (2)     [14]

1.3 Kies die onderstaande chemiese formule wat ‘n voorbeeld is van ‘n trigonale piramidevormige molekuul. (2)

TOTAL SECTION B: [80] GRAND TOTAL: [100]

1.2 All organic molecules contain at least one atom _____. (2)

  Question 5   5.1 You decide to undertake a titration experiment in order to find the concentration of a sample of potassium hydroxide. Given the following balanced equation: KOH(aq) + HCl(aq) → KCl(aq) + H20(l)   30 cm3 of a 0,2 mol·dm−3 hydrochloric acid solution was reacted with potassium hydroxide. It was found that 22 cm3 of the potassium hydroxide was needed to neutralise the acid.   5.1.1 Convert any necessary units to SI units. (2) 5.1.2 Calculate the concentration of the potassium hydroxide. (4) 5.2 Calcium oxide is a useful compound in industry. It is used to purify sugar, to soften water and in the glass and porcelain making process. 30g of CaCO3 is heated to produce CaO CaCO3 → CaO + CO2   5.2.1 What is the maximum mass calcium oxide that could be produced in this reaction? (5) 5.2.2 However, only 13g of CaO is produced. Calculate the percentage yield. (3)     [14]

SECTION B: STRUCTURED QUESTIONS The following section consists of longer structured questions. Please complete this section separately. Answer the following questions each on a separate page. Scan your answers in the correct order and upload a SINGLE PDF document, containing ALL THE ANSWERS, in the SECOND QUIZ.

1.2 Complete the following sentence: According to the VSPER theory, valence electron pairs arrange themselves so that they are as __________ as they can be. (2)

Question 6   Methane burns in oxygen, producing carbon dioxide and water. This reaction is represented by the following equation: CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)   6.1 Give the name for this type of reaction. (1) 6.2 In the reaction 4 dm3 of methane is burnt, what volume of water vapour will be produced? (2)     [3]

Question 7   If you were to have a headache, one option would be to take an aspirin. Aspirin (C9H8O4) is made from salicylic acid (C7H6O3) according to the following reaction: C7H6O3 (s) + C4H6O3 (l) → C9H8O4  (s) + CH3COOH (l)   7.1 Is this equation balanced? If not, balance it. (1) 7.2 In an aspirin factory, a small pilot study is carried out, using 250g of salicylic acid. What is the maximum mass of aspirin that could be produced? (7)     [8]

 Question 8   Ammonia is a colourless gas that is known for its unpleasant smell. In high concentrations, it is considered toxic.   8.1 What is the chemical formula for ammonia? (2) 8.2 How many lone pairs does ammonia have? (2) 8.3 Draw a Lewis diagram of the ammonia molecule. (4) 8.4 Determine the molecular shape of the chlorine trifluoride molecule. (2) 8.5 Is this a polar or non-polar molecule? Explain your answer. (3)     [13]