4NA WA2 Practice Paper from WA2 2023 (Periodic Table, Reactivity Series and Metals

PEI HWA SECONDARY SCHOOL SECONDARY FOUR NORMAL (ACADEMIC) SC(CHEM) WEIGHTED ASSESSMENT 2 2023 (modified) Name : ______________________________ ( ) Class : 4D____ Date : ___ May 2023 TG : 4________ Duration : 30 min Parent’s Signature : ____________ Section A – Multiple Choice Questions (5 marks) Choose the correct answer and write A, B, C or D in the boxes provided. Question 1 2 3 4 5 Answer D A A C A 1 Some of the general physical properties of metals are shown. 1 2 3 4 Metals are hard solids. Metals have high densities. Metals have very high melting points. Metals are good conductors of electricity. Which of these properties does lithium have? A 1 and 2 only. B 3 and 4 only. C 2 only. D 4 only. 2 In which test tube will the rusting of the iron nail occur the fastest? A B C D 25 NaCl (aq) oil cotton wool water drying agent

2 3 The table gives information about the reactivity of three metals P, Q and R. What is the order of reactivity of P, Q and R? most reactive → least reactive A P R Q B P Q R C Q R P D R P Q 4 The table below shows the results obtained when different metals were placed in different salt solutions. A tick (√) means that a solid was deposited. A cross (×) means that there is no visible reaction. metal aqueous salt solution of metal barium nitrate chromium(III) nitrate tin(IV) nitrate caesium nitrate barium √ √ × chromium × √ × tin × × × caesium √ √ √ Which row correctly arranges the four metals in order of increasing reactivity? Least reactive Most reactive A caesium barium chromium tin B chromium barium tin caesium C tin chromium barium caesium D barium caesium tin chromium

3 5 The diagram shows an outline of the Periodic Table. W Y X U V Z Which of the following statements is true? A U is more reactive than X. B V is a soft metal that can be cut with a knife. C W is a very reactive metallic element. D Y is an inert gas. Section B – Short-Answer Questions (12 marks) Answer ALL the questions in the spaces provided. 6 (a) Element Q forms a fluoride with a chemical formula QF. QF has a melting point of 988 °C. (i) Suggest whether Q is a metal or a non-metal. Metal [1] (ii) Deduce the group number which Q is found in the Periodic Table and given that Q is found in Period 3, identify Q. 1, sodium [1] (ii) Q reacts with water vigourosly to form an alkali and a gas. By using Q identified in (a)(ii), name the products formed. alkali: sodium hydroxide gas: hydrogen gas [2] (iv) Describe how you can test for the gas produced in (a)(ii). Use a lighted splint and if it gets extinguished with a ‘pop’ sound, gas produced is hydrogen. [1] (b) Unlike Q, argon gas will not react with fluorine or oxygen to form compounds. Explain why. Argon has a fully-filled valence shell / completely -filled valence shell / stable octet configuration and hence do not need to gain, lose or share electrons with other atoms. [1]

4 7 (a) Coal-fire power station emit sulfur dioxide into the atmosphere. Sulfur dioxide is a pollutant that damages the environment. (i) State a source of sulfur dioxide gas. Volcano eruption / combustion of fossil fueks [1] (ii) What type of oxide is sulfur dioxide classified as? Type of oxide: acidic oxide [1] (iii) Explain the environmental harmful effects of sulfur dioxide. Sulfur dioxide being an acidic oxide will dissolve in rainwater to produce acid rain. Acid rain • corrodes buildings and sculptures made from metal or stone • lowers the pH of soil below what many plant species can tolerate, killing them • lowers the pH of soil below what many plant species can tolerate, killing them • lowers the pH of soil below what many plant species can tolerate, killing them [2] (b) Both sulfur and oxygen belong to the same group but different periods in the Periodic Table. Using their electronic configurations, explain why (i) sulfur and oxygen belong to the same group, They both have 6 valence electrons. (ii) sulfur and oxygen belong to different periods. They both have different number of electron shells, sulfur having 3 and oxygen 2. [2]

5 Section C – Free-Response Questions (8 marks) Answer ALL the questions in the spaces provided. 9 (a) The table below gives the boiling points of some members of Group 18 in the Periodic Table. element boiling point / °C fluorine -188 chlorine -34 bromine 59 iodine 184 (i) State the common name given to Group 17 elements. Halogens [1] (ii) Explain why fluorine, chlorine, bromine, and iodine are placed in the same group in the Periodic Table. All four elements have the same number of valence electrons / 7 valence electrons. [1] (iii) Suggest the colour and physical state of chlorine at room temperature. colour yellow green physical state gas [1] (iv) In Group 17, astatine comes after iodine. Using the data in the table, predict the boiling point of astatine. Any boiling point between 300 - 350°C [1] (v) Other than changes in melting and boiling point, suggest one more trend in the physical properties going down Group 17. Any of the following [1] • Colour intensity increases down the group • Density increases down the group [1]

6 - END - (b) A student uses the set -up below to bubble fluorine gas through a colourless solution of sodium bromide. A displacement reaction occurred. (i) Describe what would is observed when fluorine gas is bubbled through the colourless solution of sodium bromide. A reddish-brown solution is formed / Solution turns reddish brown. [1] (ii) Complete the word equation for the reaction that occurs between fluorine and sodium bromide. fluorine + sodium bromide → bromine + sodium fluoride [1] (iii) Explain why a reaction can occur between fluorine and sodium bromide. Fluorine is more reactive than bromine and hence able to displace bromine from sodium bromide. [1] fluorine gas sodium bromide

7 The Periodic Table of the Elements The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p) Group I II III IV V VI VII 0 Key 1 H Hydrogen 1 2 He Helium 4 3 Li Lithium 7 4 Be Beryllium 9 proton (atomic) number atomic symbol name relative atomic mass 5 B Boron 11 6 C Carbon 12 7 N Nitrogen 14 8 O Oxygen 16 9 F Fluorine 19 10 Ne Neon 20 11 Na Sodium 23 12 Mg Magnesium 24 13 Al Aluminium 27 14 Si Silicon 28 15 P Phosphorus 31 16 S Sulfur 32 17 Cl Chlorine 35.5 18 Ar Argon 40 19 K Potassium 39 20 Ca Calcium 40 21 Sc Scandium 45 22 Ti Titanium 48 23 V Vanadium 51 24 Cr Chromium 52 25 Mn Manganese 55 26 Fe Iron 56 27 Co Cobalt 59 28 Ni Nickel 59 29 Cu Copper 64 30 Zn Zinc 65 31 Ga Gallium 70 32 Ge Germanium 73 33 As Arsenic 75 34 Se Selenium 79 35 Br Bromine 80 36 Kr Krypton 84 37 Rb Rubidium 85 38 Sr Strontium 88 39 Y Yttrium 89 40 Zr Zirconium 91 41 Nb Niobium 93 42 Mo Molybdenum 96 43 Tc Technetium - 44 Ru Ruthenium 101 45 Rh Rhodium 103 46 Pd Palladium 106 47 Ag Silver 108 48 Cd Cadmium 112 49 In Indium 115 50 Sn Tin 119 51 Sb Antimony 122 52 Te Tellurium 128 53 I Iodine 127 54 Xe Xenon 131 55 Cs Caesium 133 56 Ba Barium 137 57 – 71