Chemistry Exam 2023 Sem 1 (1).docx.pdf

IVANHOE GIRLS’ GRAMMAR SCHOOL Student name: _________________...

IVANHOE GIRLS’ GRAMMAR SCHOOL Student name: _____________________________ YEAR 10 SCIENCE - CHEMISTRY SEMESTER 1 EXAM 2023 Teachers: Miss Leong Mr Boylett (circle one) QUESTION AND ANSWER BOOKLET Section A Section B Total Percentage Multiple Choice Short Answer 15 marks 30 marks 45 marks Score Hand in Multiple Choice Answer Sheet, Exam Booklet and data booklet Instructions to Students There are two sections: Section A. 15 questions Select the best response to each question and indicate your choice on the answer sheet provided. Select only one alternative for each question. No marks will be deducted for incorrect answers. Each question is worth 1 mark Section B. 7 questions Write your answers in the space provided in the exam booklet. All responses should be written in clear English. SECTION A - Multiple Choice (15 marks) 1. In an experiment, the variable that not changed is referred to as the: A. Measurement variable. B. Independent variable. C. Controlled variable. D. Dependent variable. 2. When solutions of lithium fluoride (LiF) and lead chloride (PbCl2) are mixed, solid lead fluoride (PbF2) forms. Which ions remain dissolved in the solution? A. Li+ and Cl- B. Pb2+ and Cl- C. Li+ and F- D. Pb2+ and F- 3. The rate of a chemical reaction will increase if: A. The temperature decreases. B. The concentration of the reactants decreases. C. The surface area of the reactants decreases. D. A catalyst is used. 4. Which of the following is not a balanced equation? A. NaCl + AgNO3 → AgCl + NaNO3 B. H2 + O2 → H2O C. N2 + 3H2 → 2NH3 D. 2Na + 2H2O → 2NaOH + H2 5. Which of the following is a covalent compound? A. NaCl B. H2O C. MgO D. Fe 6. Which of the following ions does not have a charge of ‘-2’? A. Chromate. B. Sulfide. C. Phosphide. D. Oxide. 7. In the periodic table, elements are placed in the same group because they have the same: A. Mass number. B. Colour. C. Number of electron shells. D. Number of valence (outermost) electrons. 8. The mass number of an element always indicates the number of: A. Electrons + protons. B. Electrons. C. Protons + neutrons. D. Neutrons. 9. In terms of collision theory, a chemical reaction only occurs when: A. Reactants collide with little energy in the correct orientation. B. Two reactant molecules collide with each other in any orientation. C. Chemical bonds are broken by a catalyst. D. Reactants collide in correct orientation with sufficient energy. 10. In an energy level (profile) diagram, activation energy is a measure of: A. the chemical energy of the products. B. the energy required for successful collisions to occur. C. the overall amount of energy released or absorbed. D. the chemical energy of the reactants. 11. The use of fertilisers in farming leads to waste entering the waterways such as rivers. What type of pollutant would such fertilisers be classified as? A. Chemical pollutant. B. Non-chemical pollutant. C. Biological pollutant. D. Thermal pollutant. 12. When an acid was added to a solid, a reaction occurred that produced a clear solution and a colourless gas. The gas popped when a lighted match was placed in the mouth of the test-tube. The gas must have been: A. Carbon dioxide. B. Oxygen. C. Hydrogen. D. Nitrogen.  Use the following information to answer question 13. Element Charge formed by the element V +1 W +2 X -1 Y -2 Z -3 13. A possible formula for an ionic compound by the above elements could be: A. VW B. XZ C. W2Y D. W3Z2 14. Antonio completed an experiment in which he recorded a series of observations. Which of the following observations would be a quantitative observation? A. The reaction finished after thirty-six seconds. B. The solution turned a bright blue colour. C. The reactant produced a smelly odour. D. The beaker felt warm. 15. Which of the following is the correct naming for the following groups Group 18 Group 17 A. Transition metals Noble gases B. Noble gases Transition metals C. Halogens Noble gases D. Noble gases Halogens SECTION B - Short Answer (30 marks) Question 1 A B C D E F G H K M O L Selecting only from the element symbols labelled on this Periodic table, write the letter (A, B, C, D, E, F, H, K, M, O, L) corresponding to the element that: i. Is an alkali earth metal in period 4: ____________ ii. Has an electron configuration of 2. 8. 3 : ____________ iii. Is in period 3 and has 5 electrons in the outermost shell: _____________ iv. Has a full outer shell of electrons: ___________________________ v. Would form an ion with a charge of -1: _____________ vi. Is a metal with one valence electron: _____________ [6 x 0.5 = 3 marks] Question 2 Complete the following table: Name of ionic compound Ions Formula of ionic compound FeI3 Ag+ SCN- [4 marks] Question 3 A class of students carried out an investigation to find out whether the concentration of the acid used had any effect on the time taken for a ribbon of Aluminium to react completely. Equal volumes of aqueous Sulfuric acid (H2SO4) and equal lengths of solid Aluminium (Al) ribbon were used in each test. The table below shows a set of results. The products of the reaction were an aqueous solution of Aluminium sulfate (Al2(SO4)3) and Hydrogen gas (H2). While the reaction proceeded, the beaker was hot to touch. Time taken for Aluminium to react Concentration of acid /M completely/seconds. 2.0 13 1.5 22 1.2 30 0.8 70 0.6 145 0.5 250 a) Write a balanced formula equation for the reaction occurring in the beaker. Include appropriate states (s), (l), (aq) or (g): ___________________________________________________________________ [2 marks] b) Identify the following variables for this investigation: Independent variable: ____________________________ Dependent variable: _____________________________ [2 marks] c) Write a hypothesis for this investigation: ___________________________________________________________________ ___________________________________________________________________ [1 mark]  d) State one safety precaution that should be included in the risk assessment before the students started the investigation. ___________________________________________________________________ [1 mark] e) State two examples of observations that the students could use to confirm that a chemical reaction has taken place. ___________________________________________________________________ ___________________________________________________________________ [2 marks] f) Explain the recorded results with reference to collision theory. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ [2 marks] Question 4 Calcium can exist as either a solid metal or as an ion bonded with an ionic substance. Complete the following about each form of Calcium: Element Symbol Atomic Electron configuration Number Calcium-40 Ca Calcium ion 20 [4 x 0.5 = 2 marks] Question 5 When acid reacts with Zinc metal, Hydrogen gas will be produced. Complete the following table about the properties of Zinc and Hydrogen gas: Substance Zinc metal Hydrogen gas Name the type of Bonding present Write a description of bonding Do or do not conduct electricity Malleable or not malleable State one other property of each substance [5 marks] Question 6 Draw a labelled diagram of the bonding arrangement that would be found in an ionic substance under the following conditions: Solid Dissolved in water [2 marks] Question 7 Two students wanted to investigate the reactivity of aqueous Potassium carbonate. They reacted an aqueous solution of Potassium carbonate solution with an aqueous solution of Barium nitrate. a) Name the type of reaction that would occur between the aqueous solutions of Potassium carbonate and the Barium nitrate. ___________________________________________________________________ [1 mark] b) Write a word equation then a balanced chemical equation for the reaction that would occur between the aqueous solutions of Potassium carbonate and the Barium nitrate. Word equation: ___________________________________________________________________ [1 mark] Balanced Chemical equation: (include appropriate states of matter such as (s), (l), (g) or, (aq).) ___________________________________________________________________ [2 marks]