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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]

1.8 ’n Monster koolwaterstof bevat 82,75% koolstof per massa. Die empiriese formule van die verbinding sal _____ wees. (2)

1.4 Choose the correct term to complete the following sentence; In a non-polar molecule, the charge is ________ spread across the molecule. (2)

1.8 The gas law that defines the enclosed volume of a gas to its temperature (in Kelvin), provided pressure and amount of gas remain constant is: (2)

1.5 Name the type of intermolecular force that the following situation describes: The intermolecular force between an ion and a non-polar molecule, leading to a weak, short lived force which holds the compounds together. (2)

VRAAG 6 0,5mol H2(g) en 0,6mol Br2(g) word in ’n 5,0dm3 fles saamgevoeg en verhit tot 700 K. Die reaksie is eksotermies: H2(g) + Br2(g) → 2HBr(g) 6.1 Die konsentrasie HBr in die fles by ewewig is 0,17 mol.dm-3. Bereken Kc. (8) 6.2 Wanneer die temperatuur vermeerder word, sal die Kc-waarde VERMEERDER, VERMINDER of DIESELFDE BLY? Gebruik Le Chatelier se beginsel om jou antwoord te verduidelik. (4) 6.3 Beskou die volgende grafiek en beantwoord die vrae wat volg:   Regterklik op die onderstaande blou blokkie om die diagram vir Vraag 6 in ‘n nuwe venster oop te maak.       6.3.1 Skryf ’n gebalanseerde vergelyking wat die eksotermiese reaksie wat plaasvind, verteenwoordig. (3) 6.3.2 Gee die tyd (tye) wanneer die stelsel ewewig bereik. (2) 6.3.3 Noem die versteuring wat by 14 s plaasgevind het. (2) 6.3.4 Hoe sal die waarde van die ewewigskonstante na hierdie versteuring verander? Skryf slegs VERMEERDER, VERMINDER of BLY DIESELFDE. Gee ’n rede vir jou antwoord. (3) 6.3.5 Noem die toestande nodig vir die reaksie om ewewig te bereik. (2) 6.3.6 Noem een ander toestand wat die ewewig in hierdie reaksie sal beinvloed en verduidelik wat die effek op die Kc-waarde sal wees indien hierdie toestand verhoog. (3)     [27]

Question 2   2.1 Name the type of bond that can be formed between an atom with no unpaired electrons and an atom with a lone pair. (2) 2.2 Which of the following reactions will not take place? Give the correct letter and explain your answer. A. H + H → H2 B. Ar + Ar → Ar2 C. Cl + Cl → Cl2 D. O + O → O2 (2) 2.3 Draw a Lewis diagram of a formaldehyde molecule (CH2O). (3) 2.4 Balance the following chemical equation: Au2S3 + H2 → Au + H2S (4)     [11]