Physical Sciences Grade 10 P2 2018 QP (Eng)

NATIONAL SENIOR CERTIFICATE GRADE 10 PHYSICAL SCIENCES: CHEMISTRY (P2) NOVEMBER 2018 MARKS: 150 TIME: 2 hours This question paper consists of 14 pages and 2 data sheets. Copyright reserved Please turn over

Physical Sciences/P2 2 DBE/November 2018 CAPS – Grade 10 INSTRUCTIONS AND INFORMATION 1. Write your name and class (e.g. 10A) in the appropriate spaces on the ANSWER BOOK. 2. This question paper consists of TEN questions. Answer ALL the questions in the ANSWER BOOK. 3. Start EACH question on a NEW page in the ANSWER BOOK. 4. Number the answers correctly according to the numbering system used in this question paper. 5. Leave ONE line between two subquestions, e.g. between QUESTION 2.1 and QUESTION 2.2. 6. You may use a non-programmable calculator. 7. You may use appropriate mathematical instruments. 8. You are advised to use the attached DATA SHEETS. 9. Show ALL formulae and substitutions in ALL calculations. 10. Round off your final numerical answers to a minimum of TWO decimal places. 11. Give brief motivations, discussions, etc. where required. 12. Write neatly and legibly. Copyright reserved Please turn over

Physical Sciences/P2 3 DBE/November 2018 CAPS – Grade 10 QUESTION 1: MULTIPLE-CHOICE QUESTIONS Various options are provided as possible answers to the following questions. Each question has only ONE correct answer. Choose the answer and write only the letter (A–D) next to the question numbers (1.1 to 1.10) in the ANSWER BOOK, e.g. 1. 11 D. 1.1 Which ONE of the following substances is NOT a pure substance? A Iron B Sugar C Steel D Graphite (2) 1.2 The CORRECT chemical formula for potassium nitrate is … A K3N B PNO 3 C KNO 3 D K 2 NO 3 (2) 1.3 Different isotopes of the same element have different … A atomic numbers. B numbers of neutrons. C numbers of protons. D numbers of electrons. (2) 1.4 Which ONE of the following ionisation equations represents the second ionisation of magnesium? A Mg(g) + energy → Mg+ + e- B Mg+ (s) + energy → Mg2+ + 2e- C Mg+ (g) + energy → Mg2+ + 2e- D Mg(s) + energy → Mg+ + e- (2) Copyright reserved Please turn over

Physical Sciences/P2 4 DBE/November 2018 CAPS – Grade 10 1.5 Which PAIR of elements is most likely to have a similar arrangement of outer electrons and similar chemical behaviour? A Boron and aluminium B Helium and fluorine C Carbon and nitrogen D Chlorine and oxygen (2) 1.6 Which ONE of the following statements is INCORRECT about the properties of a physical change? A When a physical change occurs, the compounds may rearrange themselves, but the bonds in between the atoms will not break. B Physical change in matter is reversible. C Energy is absorbed when matter changes from a solid to a liquid. D Molecules are not conserved during a physical change. (2) 1.7 In the compound, H2 O , the ratio of the MASS of hydrogen to oxygen is always … A 1 : 2. B 2 : 1. C 1 : 8. D 1 : 16. (2) 1.8 One mole of H2 SO4 contains … A 7 atoms. B 1 molecule. C 6,02×1023 molecules. D 42,14×1023 molecules. (2) Copyright reserved Please turn over

Physical Sciences/P2 5 DBE/November 2018 CAPS – Grade 10 1.9 Which ONE of the following solutions will NOT form a precipitate if added to a solution of silver nitrate? A NaCl(aq) B MgBr2 (aq) C KI(aq) D Mg(NO3 )2 (aq) (2) 1.10 The sphere in which minerals are found is known as … A atmosphere. B biosphere. C lithosphere. D stratosphere. (2) [20] Copyright reserved Please turn over

Physical Sciences/P2 6 DBE/November 2018 CAPS – Grade 10 QUESTION 2 (Start on a new page.) The diagram below shows three different substances, P, Q and R. SUBSTANCE P SUBSTANCE Q SUBSTANCE R KEY Hydrogen Chlorine Oxygen Sulphur Sodium Iron 2.1 Define the term element. (2) Use the diagram and the key provided to answer the questions that follow. 2.2 Write down a LETTER that represents the following: 2.2.1 Pure substance (1) 2.2.2 Homogeneous mixture (1) 2.2.3 Heterogeneous mixture (1) 2.3 Indicate whether the pure substance identified in QUESTION 2.2.1 is an element or a compound. (1) 2.4 Which physical method would you use to separate substance Q into its components? (1) 2.5 Write down the physical property upon which the separation techniques are based to separate the following substances into their individual components: 2.5.1 Q (1) 2.5.2 R (1) [9] Copyright reserved Please turn over

Physical Sciences/P2 7 DBE/November 2018 CAPS – Grade 10 QUESTION 3 (Start on a new page.) The vapour pressure versus temperature graph below was obtained for four unknown liquids (A, B, C and D). Atmospheric pressure is measured as 101,3 kPa. Vapour pressure versus temperature 200 A B C 150 Vapour pressure (kPa) D 101,3 kPa 100 50 0 0 25 50 75 100 125 Temperature (°C) 3.1 Define the term boiling point. (2) Use the information given in the graph to answer the questions that follow. 3.2 Write down the: 3.2.1 Boiling point of liquid B (1) 3.2.2 Liquid which remains a liquid at 115 °C (1) 3.2.3 Liquid that is most likely to be water (1) 3.3 State the PHASE CHANGE that takes place at the stage when the vapour pressure is equal to atmospheric pressure. (1) 3.4 What happens to the temperature of a liquid during a phase change? Write down only INCREASES, DECREASES or REMAINS THE SAME. (1) 3.5 Explain the answer to QUESTION 3.4. (2) 3.6 Which liquid (A, B, C or D) has the weakest intermolecular forces? Give a reason for the answer. (3) 3.7 What is the relationship between vapour pressure of the liquid and temperature? (2) [14] Copyright reserved Please turn over

Physical Sciences/P2 8 DBE/November 2018 CAPS – Grade 10 QUESTION 4 (Start on a new page.) Study the table below and answer the questions that follow. ELEMENT/ION NUMBER OF NUMBER OF NUMBER OF PROTONS NEUTRONS ELECTRONS P 11 12 11 Q 14 16 14 R 16 16 18 4.1 Define the term atomic number. (2) 4.2 Write down the: 4.2.1 Chemical symbol of element Q using the notation AZX (2) 4.2.2 Element (P, Q or R) that is an alkali metal (1) 4.2.3 Chemical symbol of R (2) 4.3 Element P reacts with oxygen to form the compound with the chemical formula P 2 O. 4.3.1 Predict the chemical formula that element Rb in the periodic table will form when it reacts with oxygen. (2) 4.3.2 Explain the answer to QUESTION 4.3.1. (2) 4.4 What is the trend in ionisation energy as you move from element P to element R? Write down only INCREASES, DECREASES or REMAINS THE SAME. Explain the answer. (4) 4.5 How many electrons does an ION of element P have? Draw the Aufbau diagram of this ion. (3) 4.6 When orbitals of identical energy are available, electrons are placed in individual orbitals before they are paired. Give the name of this rule. (1) 4.7 Element Y occurs as these isotopes in the following proportions: Y – 28(92,23%); Y – 29(4,68%); Y – 30(3,09%) Calculate the relative atomic mass of element Y. (3) [22] Copyright reserved Please turn over

Physical Sciences/P2 9 DBE/November 2018 CAPS – Grade 10 QUESTION 5 (Start on a new page.) Study the physical and chemical processes below and answer the questions that follow. X: H2 O(s) → H2 O(g) Y: CaCO3 (s) → CaO(s) + CO2(g) ∆ Z: Iron + Oxygen → Iron(III) oxide 5.1 Define the term physical change. (2) 5.2 Write down the LETTER of the process that represents the following: 5.2.1 Physical change (1) 5.2.2 Decomposition reaction (1) 5.3 Give the name of the physical change stated in QUESTION 5.2.1. (1) 5.4 State TWO properties of a reaction that indicate that a chemical change has taken place. (2) 5.5 For process Z, write down: 5.5.1 What the symbol ∆ represents (1) 5.5.2 A BALANCED CHEMICAL EQUATION (Show the phases of ALL reactants and products.) (4) 5.6 A 20 g sample of CaCO3 (s) in process Y decomposes to form 11,2 g of CaO. In a second sample, 30 g decomposes to form x g of CO2 . 5.6.1 State the law of constant composition. (2) 5.6.2 Use the law in QUESTION 5.6.1 to calculate mass 𝑥 of the CO2 formed. (4) [18] Copyright reserved Please turn over

Physical Sciences/P2 10 DBE/November 2018 CAPS – Grade 10 QUESTION 6 (Start on a new page.) Study the diagram below showing structures of two different substances (A and B) and answer the questions that follow. SUBSTANCE A SUBSTANCE B 6.1 Choose the substance (A or B) that describes the following: 6.1.1 Metallic structure (1) 6.1.2 Structure of magnesium chloride (1) 6.2 Explain how the type of bond in substance A forms. (2) 6.3 Name the type of bond that exists in substance B. (1) 6.4 Magnesium and chlorine react to form compound magnesium chloride. 6.4.1 Define the term compound. (2) 6.4.2 Write down the NAME of the group to which magnesium belongs. (1) 6.4.3 Write down the valency of a chlorine atom. (1) 6.4.4 Use the Lewis dot diagram to show the formation of magnesium chloride. (3) [12] Copyright reserved Please turn over

Physical Sciences/P2 11 DBE/November 2018 CAPS – Grade 10 QUESTION 7 (Start on a new page.) A group of learners prepare a 0,25 mol∙dm-3 solution of sodium carbonate by dissolving a 14,2 g sample of hydrated sodium carbonate (Na 2 CO 3 ∙xH 2 O) in 200 cm3 of water. 7.1 Explain the meaning of the term hydrated. (1) 7.2 Write down a BALANCED CHEMICAL EQUATION to show how sodium carbonate dissociates in water. (2) 7.3 Learners then take 10 cm3 of the prepared solution and allow it to react completely with 5 cm3 of dilute hydrochloric acid, according the following balanced chemical equation: Na2 CO3 + 2HCl → 2NaCl + H2 O + CO2 7.3.1 Define the term a mole of a substance. (2) 7.3.2 What type of chemical reaction is represented by the chemical equation above? (1) 7.3.3 Calculate the number of moles of hydrochloric acid in 5 cm3 of hydrochloric acid if its concentration is 1 mol∙dm-3. (3) 7.4 Calculate the mass of sodium chloride formed in the reaction in QUESTION 7.3. (5) [14] Copyright reserved Please turn over

Physical Sciences/P2 12 DBE/November 2018 CAPS – Grade 10 QUESTION 8 (Start on a new page.) Learners investigate how the type of substance affects electrical conductivity of the substance. They conduct three experiments using three different substances under the same conditions, as shown in the table below. EXPERIMENT MASS OF TYPE OF TEMPERATURE SUBSTANCE (g) SUBSTANCE (°C) 1 2 Solution of CaCl 2 25 2 2 Solution of KCl 25 3 2 Solution of sugar 25 8.1 Define the term electrolyte. (2) 8.2 For the investigation, write down the: 8.2.1 Investigative question (2) 8.2.2 Dependent variable (1) 8.2.3 Independent variable (1) 8.2.4 Controlled variable (1) 8.3 For the investigation, predict with reasons the substance that will yield the following: 8.3.1 The highest conductivity (2) 8.3.2 Zero conductivity (2) 8.4 The substance tested in Experiment 3 was analysed. It was found to contain 40% carbon, 6,67% hydrogen and 53,33% oxygen. Determine the molecular formula if the molar mass is 180 g∙mol-1. (7) [18] Copyright reserved Please turn over

Physical Sciences/P2 13 DBE/November 2018 CAPS – Grade 10 QUESTION 9 (Start on a new page.) Two test tubes, A and B, both contain a sodium salt solution. After a small amount of barium chloride is added, the solution in both test tubes forms a white precipitate. Barium chloride solution Test tube A Test tube B 9.1 Write down the type of reaction that takes place in the test tubes. (1) 9.2 A concentrated nitric acid solution is then added into each test tube to establish which one contains carbonate ions and which one contains sulphate ions. Bubbles are formed in test tube A. There is no reaction in test tube B. Test tube A Test tube B 9.2.1 Identify which IONS (CARBONATE or SULPHATE) are present in test tube B. (1) 9.2.2 Write down a BALANCED CHEMICAL EQUATION that represents the reaction between nitric acid and the precipitate formed in test tube A. (3) 9.3 A solution of sodium carbonate was prepared by dissolving 5 g of the powder in 100 cm3 of water. The solution reacted with a barium chloride solution, according to the following balanced chemical equation: Na2 CO3 (aq)+ BaCl2 (aq) → BaCO3 (s) + 2NaCl(aq) 9.3.1 Calculate the mass of barium carbonate that should form in this reaction. (5) It was found that only 8,3 g precipitate formed. 9.3.2 Calculate the percentage yield. (2) [12] Copyright reserved Please turn over

Physical Sciences/P2 14 DBE/November 2018 CAPS – Grade 10 QUESTION 10 (Start on a new page) The diagram below shows how the hydrosphere is linked to the biosphere. Study the diagram and answer the questions that follow. A Water B PLANTS vapour CLOUDS C 10.1 Differentiate between the hydrosphere and biosphere. (2) 10.2 Write down the name of process: 10.2.1 A (1) 10.2.2 B (1) 10.2.3 C (1) 10.3 Describe the energy changes during processes A and B. Write down only ENERGY GAINED or ENERGY LOST. (2) 10.4 Describe the interaction between the hydrosphere and plants. (4) [11] TOTAL: 150 Copyright reserved

Physical Sciences/P2 DBE/November 2018 CAPS – Grade 10 DATA FOR PHYSICAL SCIENCES GRADE 10 PAPER 2 (CHEMISTRY) GEGEWENS VIR FISIESE WETENSKAPPE GRAAD 10 VRAESTEL 2 (CHEMIE) TABLE 1: PHYSICAL CONSTANTS/TABEL 1: FISIESE KONSTANTES NAME/NAAM SYMBOL/SIMBOOL VALUE/WAARDE Standard pressure pθ 1,013 x 105 Pa Standaarddruk Molar gas volume at STP Vm 22,4 dm3∙mol-1 Molêre gasvolume by STD Standard temperature Tθ 273 K Standaardtemperatuur Charge on electron e 1,6 x 10-19 C Lading op elektron TABLE 2: FORMULAE/TABEL 2: FORMULES m N n= n= M NA n m V c= OR/OF c = n= V MV Vm Copyright reserved

Physical Sciences/P2 DBE/November 2018 CAPS – Grade 10 TABLE 3: THE PERIODIC TABLE OF ELEMENTS/TABEL 3: DIE PERIODIEKE TABEL VAN ELEMENTE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 (I) (II) (III) (IV) (V) (VI) (VII) (VIII) Atomic number 1 KEY/SLEUTEL Atoomgetal 2 2,1 H He 1 29 4 3 4 Electronegativity Symbol 5 6 7 8 9 10 Elektronegatiwiteit 1,9 Cu Simbool 1,0 Li 1,5 Be 63,5 2,0 B 2,5 C 3,0 N 3,5 O 4,0 F Ne 7 9 11 12 14 16 19 20 11 12 13 14 15 16 17 18 Approximate relative atomic mass 0,9 Na 1,2 Mg Benaderde relatiewe atoommassa 1,5 Aℓ 1,8 Si 2,1 P 2,5 S 3,0 Cℓ Ar 23 24 27 28 31 32 35,5 40 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 0,8 K 1,0 Ca 1,3 Sc 1,5 Ti 1,6 V 1,6 Cr 1,5 Mn 1,8 Fe 1,8 Co 1,8 Ni 1,9 Cu 1,6 Zn 1,6 Ga 1,8 Ge 2,0 As 2,4 Se 2,8 Br Kr 39 40 45 48 51 52 55 56 59 59 63,5 65 70 73 75 79 80 84 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 0,8 Rb 1,0 Sr 1,2 Y 1,4 Zr Nb 1,8 Mo 1,9 Tc 2,2 Ru 2,2 Rh 2,2 Pd 1,9 Ag 1,7 Cd 1,7 In 1,8 Sn 1,9 Sb 2,1 Te 2,5 I Xe 86 88 89 91 92 96 101 103 106 108 112 115 119 122 128 127 131 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 0,7 Cs 0,9 Ba La 1,6 Hf Ta W Re Os Ir Pt Au Hg 1,8 Tℓ 1,8 Pb 1,9 Bi 2,0 Po 2,5 At Rn 133 137 139 179 181 184 186 190 192 195 197 201 204 207 209 87 88 89 0,7 Fr 0,9 Ra Ac 58 59 60 61 62 63 64 65 66 67 68 69 70 71 226 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 140 141 144 150 152 157 159 163 165 167 169 173 175 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 232 238 Copyright reserved