XMS SEC 3 WA2 2023 QP

3 6092/Chemistry/2023 Term 2 Weighted Assessment Section A Answer all questions. Write your answers in the boxes provided at the end of the Section. 1 Which of the following elements would be expected to form the largest ion (most number of electron shells) with a noble gas configuration? A oxygen B fluorine C potassium D magnesium 2 Element P has an electronic configuration of 2.8.8.2. Element Q has an electronic configuration of 2.8.7. What is the likely chemical formula of the compound containing only P and Q? A P7Q2 B PQ2 C P2Q D PQ 3 A piece of zinc strip is burnt in oxygen to form zinc oxide. Which of the following chemical equation is correct? A 2Zn + O2 → 2ZnO B 2Zn + O → Zn2O C Zn + O2 → ZnO2 D Zn + O → ZnO

4 6092/Chemistry/2023 Term 2 Weighted Assessment 4 Which particles enable the conduction of electricity through metals? A positive ions and electrons B positive ions and negative ions C positive ions only D electrons only 5 Which chemical equation is not balanced? A C6H12O6 + 3O2 → 6CO2 + 6H2O B 2HCl + CaCO3 → CaCl2 + CO2 + H2O C 2KClO3 → 2KCl + 3O2 D 4P + 5O2 → 2P2O5 Question 1 2 3 4 5 Answer

5 6092/Chemistry/2023 Term 2 Weighted Assessment For Examiner’s Use Section B Answer all questions. Write your answers in the spaces provided. 6 Balance the following chemical equations. (a) ………. S8 + ………. O2 → ………. SO3 [1] (b) ………. C3H8 + ………. O2 → ………. CO2 + ………. H2O [1] (c) ………. AlBr3 + ………. K2SO4 → ………. KBr + ………. Al2(SO4)3 [1] [Total: 3 marks] 7 Scandium is a metallic element with the symbol Sc and atomic number 21. (a) Describe the structure of a piece of scandium. …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. [2] (b) Scandium oxide has the chemical formula Sc2O3. Write the chemical formula of scandium sulfate and scandium hydroxide. (i) scandium sulfate …………………………………. [1] (ii) scandium hydroxide …………………………………. [1] [Total: 4 marks]

6 6092/Chemistry/2023 Term 2 Weighted Assessment For Examiner’s Use 8 Carbon is a highly versatile element that exists in different forms such as diamond, graphite and fullerene. Figure 7.1 shows the structure of graphite. Figure 7.1 An example of fullerene is the buckyball, which consists of 60 carbon atoms, covalently bonded in a cage -like structure (made of twenty hexagons and twelve pentagons), and resembles a soccer ball. Figure 7.2 belows shows the structure of a buckyball,C60. Figure 7.2 Flat layer of carbon atoms. Each carbon atom in graphite is joined to only three other carbon atoms. Weak forces held the layers of carbon atoms together. Strong bonds exist between carbon atoms in a layer. Flat layer of ca