11589 18 Cisplatin was first described by Peyrone in 1845 and was approved for use in the treatment of testicular and ovarian cancers in the USA in 1978. Pt Cl H3N cisplatin NH3 Cl (a) Explain why cisplatin is effective in acting as an anticancer drug. [1] (b) Cisplatin has a number of undesired side-effects which are believed to be caused by the drug activating before it reaches the targeted tumour. Attempts to reduce these side-effects have included modifying the structure to give derivatives such as carboplatin. Pt O O carboplatin H3N H3N O O Give the molecular formula of carboplatin. [1] 11589 (c) Another method of developing more targetable platinum-based anticancer drugs has been through the development of photoactivable drugs which are activated through photoreduction by light. Early examples of these were diiodo complexes. Pt I H3N B I H3N Pt I H3N A I OH OH H3N (i) Explain, using oxidation states, why converting A into B is regarded as a reduction. [2] (ii) Describe the change in both shape and co-ordination number in converting A into B. [4] THIS IS THE END OF THE QUESTION PAPER 237486 Permission to reproduce all copyright material has been applied for. In some cases, efforts to contact copyright holders may have been unsuccessful and CCEA will be happy to rectify any omissions of acknowledgement in future if notified. DO NOT WRITE ON THIS PAGE Periodic Table of the Elements For the use of candidates taking Advanced Subsidiary and Advanced Level Chemistry Examinations Copies must be free from notes or additions of any kind. No other type of data booklet or information sheet is authorised for use in the examinations. gce A/AS examinations chemistry (advanced) 227 89 139 57 256 101 223 87 226 88 140 58 141 59 144 60 147 61 150 62 152 63 157 64 159 65 162 66 165 67 167 68 169 69 173 70 175 71 232 90 231 91 238 92 237 93 242 94 243 95 247 96 245 97 251 98 254 99 253 100 254 102 257 103 133 55 137 56 178 72 181 73 184 74 186 75 190 76 192 77 195 78 197 79 201 80 89 39 91 40 103 45 85 37 88 38 93 41 96 42 99 43 101 44 106 46 108 47 112 48 131 54 222 86 210 85 210 84 209 83 207 82 204 81 84 36 79 34 73 32 40 20 39 19 45 21 48 22 51 23 52 24 55 25 56 26 59 27 59 28 64 29 65 30 11 5 12 6 14 7 16 8 19 9 20 10 4 2 40 18 35.5 17 32 16 31 15 28 14 27 13 70 31 75 33 80 35 115 49 119 50 122 51 128 52 127 53 23 11 24 12 7 3 9 4 1 1 * 58–71 Lanthanum series † 90–103 Actinium series a = relative atomic mass (approx.) x = atomic symbol b = atomic number THE PERIODIC TABLE OF ELEMENTS Group a b x 0 VII VI V IV III II I * † One mole of any gas at 20 °C and a pressure of 1 atmosphere (105 Pa) occupies a volume of 24 dm3. Planck Constant = 6.63 × 10–34 J s Gas Constant = 8.31 J mol–1 K–1 Avogadro Constant = 6.02 × 1023 mol–1