16 (1410U30-1) 16 © WJEC CBAC Ltd. 12. A student was provided with five ionic solids containing familiar cations and anions. Each solid contains a different cation. The solids were labelled A, B, C, D and E. The student attempted to dissolve all five solids in water. She then attempted to dissolve those that did not dissolve in water in a stoichiometric amount of acid. The results are given below. Solid Addition of water Addition of dilute sulfuric acid to solid Addition of dilute nitric acid to solid A dissolves giving colourless solution 1 B dissolves giving colourless solution 2 C does not dissolve pale blue solution 3 forms upon warming with the acid D does not dissolve effervescence and solution 4 forms E does not dissolve some effervescence but the solid does not dissolve effervescence and solution 5 forms Pairs of the solutions formed were mixed and the observations recorded. Solution 5 Solution 4 Solution 3 Solution 2 Solution 1 (formed by dissolving solid A) no visible change white precipitate white precipitate bright yellow precipitate Solution 2 (formed by dissolving solid B) no visible change no visible change brown solution with a white solid Solution 3 (formed by reacting solid C with acid) thick white precipitate no visible change Solution 4 (formed by reacting solid D with acid) thick white precipitate Flame tests Flame tests carried out on solutions 1, 2, 3, 4 and 5 gave no colour with one solution, an apple- green flame with another and a lilac flame with a third. The student noted unfamiliar flame test colours for the other two solutions. (1410U30-1) Turn over. 17 17 © WJEC CBAC Ltd. Examiner only (a) Suggest which anion is present in substances D and E. Give a reason for your answer. [2] (b) Use all the information provided to suggest identities for compounds A-E. Explain clearly how you identified compounds A and C. [6 QER] A ......................................................................................................... B ......................................................................................................... C ......................................................................................................... D ......................................................................................................... E ......................................................................................................... Explanation END OF PAPER 8 18 (1410U30-1) 18 © WJEC CBAC Ltd. BLANK PAGE PLEASE DO NOT WRITE ON THIS PAGE (1410U30-1) Turn over. 19 19 © WJEC CBAC Ltd. Question number Additional page, if required. Write the question number(s) in the left-hand margin. Examiner only (1410U30-1) 20 20 © WJEC CBAC Ltd. Question number Additional page, if required. Write the question number(s) in the left-hand margin. Examiner only