XMS SEC 3 WA1 2020 QP

3 6092/Chemistry/2020 WA1 Section A [5 marks] Answer all questions. Write your answers in the boxes provided at the end of the Section. 1 When the glass plate is removed from the setup on the left, the colour of the gas in the setup becomes same for both jars after several days as shown in the diagram on the right. Which statement best explains the appearance after a few days? A Heavier particles sink while lighter particles rise. B Both the air and bromine particles diffuse at the same rate. C There are as many air particles as bromine particles in each jar. D Both the air and bromine particles move randomly. 2 The ions S 16 32 2- and C𝑙 17 35 - have the same 1: number of electrons 2: number of protons 3: number of neutrons A 1 only B 2 and 3 only C 1 and 2 only D 1 and 3 only

4 6092/Chemistry/2020 WA1 3 Which of the following groups consists of a metallic element, an ionic compound and a gaseous mixture? A bronze, sodium chloride, sea water B air, tungsten, sodium bromide C sodium, bronze, air D silicon, aluminium oxide, sea water 4 Which pair of gases will cause the water level in the left side of the tube to fall? X Y A N2 CO B Ne F2 C SO2 NO2 D Cl2 CO2

5 6092/Chemistry/2020 WA1 5 Which of the following is an ionic substance? A CO2 B Cl2O C K2O D SiO2 Write your answers for Section A in the boxes below. 1. 2. 3. 4. 5. [Total: 5]

6 6092/Chemistry/2020 WA1 Section B [30 marks] Answer all questions. Write your answers in the spaces provided. B1 The table below gives the number of protons, neutrons and electrons in some particles. Particle Proton Neutron Electron A 17 18 18 B 17 20 17 C 17 18 17 D 16 16 16 E 16 16 18 (a) (i) Which particles are negative ions? …………………………………………………………………………………………. [1] (ii) Which two atoms are isotopes? …………………………………………………………………………………………. [1] (iii) Which particle is able to form a compound with a calcium atom in a 1:1 ratio? …………………………………………………………………………………………. [1] (iv) What is the nucleon number of particle B? …………………………………………………………………………………………. [1] (v) What element is particle D? …………………………………………………………………………………………. [1] (vi) What is the charge of particle E? …………………………………………………………………………………………. [1] (b) (i) Magnesium chloride is an ionic salt. Describe the structure and bonding of this ionic compound. …………………………………………………………………………………………. …………………………………………………………………………………………. …………………………………………………………………………………………. [3] (ii) Draw a ‘dot-and-cross’ diagram of magnesium chloride. Show outer electrons only. [3] [Total: 12]

7 6092/Chemistry/2020 WA1 B2 The following graph shows a heating curve of an unknown substance. (a) (i) What is the melting point of the unknown substance? …………………………………………………………………