6   3 This question is about the elements in Group 7 of the Periodic Table and some of their compounds. (a) What is the colour of iodine in the solid and gas states? (1) Colour of iodine solid Colour of iodine gas A purple brown B purple purple C grey/black brown D grey/black purple (b) Which of these reactions occurs? (1) A Br2(aq) + 2NaCl(aq) → 2NaBr(aq) + Cl2(aq) B Br2(aq) + 2NaF(aq)  → 2NaBr(aq) + F2(aq) C Cl2(aq) + 2NaBr(aq) → 2NaCl(aq) + Br2(aq) D Cl2(aq) + 2NaF(aq)   → 2NaCl(aq) + F2(aq) (c) The halogens can form halide ions during reactions. Complete the electronic configuration of the chloride ion. (1) 1s2 ....................................................................................................................................... Turn over 7   (d) The standard electrode potentials for two half‑equations involving bromine are given. Br2(aq) + 2e–  2Br–(aq) E d = +1.09 V 2HOBr(aq) + 2H+(aq) + 2e–  Br2(aq) + 2H2O(l) E d = +1.57 V (i) Explain why the disproportionation of bromine in water is not thermodynamically feasible under standard conditions. Include the overall equation for the disproportionation and its E d cell value. (3) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (ii) Bromine disproportionates in water to a small extent at 298 K. Give a possible reason why this reaction occurs. (1) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... 8   (e) The hydrogen halides have the general formula HX, where X represents the symbol of the halogen. (i) Which diagram shows the trend in the boiling temperatures of the hydrogen halides? (1) 300 250 200 150 Boiling temperature / K HF HCl HBr HI A 300 250 200 150 Boiling temperature / K HF HCl HBr HI B Hydrogen halide Hydrogen halide Hydrogen halide Hydrogen halide 300 250 200 150 Boiling temperature / K HF HCl HBr HI C 300 250 200 150 Boiling temperature / K HF HCl HBr HI D (ii) What type of reaction occurs when ammonia gas reacts with hydrogen chloride gas? (1) A acid‑base B displacement C redox D substitution (Total for Question 3 = 9 marks) Turn over 9   4 This question is about structure and bonding. (a) Ionic bonding is the strong electrostatic attraction between (1) A anions and cations B atoms and delocalised electrons C cations and delocalised electrons D two nuclei and a shared pair of electrons (b) An aqueous solution of copper(II) chromate(VI) was electrolysed using the apparatus shown in the diagram. 6 V DC F – + copper(II) chromate(VI) solution E Deduce the colours of the solutions in regions E and F after the electrolysis has occurred. (2) Colour in region E ...................................................................... Colour in region F ...................................................................... 10   (c) Some ionic radii are given in the table. Ion Ionic radius / nm Na+ 0.102 Mg2+ 0.072 Cl– 0.180 Br– 0.195 Deduce the formula of the compound, formed from the ions in the table, that has the strongest ionic bonding. (1) .................................................................................................................................................................................................................................................................................... (d) The names of four substances are given. Substance Name P copper Q iodine R silicon(IV) oxide S sodium chloride (i) Which of these substances exists at room temperature as a giant lattice of oppositely charged ions? (1) A Substance P B Substance Q C Substance R D Substance S Turn over 11   (ii) Which of these substances has a high melting temperature, and conducts electricity when solid and when molten? (1) A Substance P B Substance Q C Substance R D Substance S 12   *(e) Water has two significant anomalous properties: • it has a higher melting temperature than hydrogen sulfide, H2S, even though it has fewer electrons in its molecules • the density of ice at 0 °C is less than that of water at 0 °C. Explain these properties. You should include a labelled diagram to show the intermolecular forces between two molecules of water. (6) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... Turn over 13   .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (Total for Question 4 = 12 marks)