Edexcel Jun 2016 Paper 2 Q15

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15 Hydrated magnesium nitrate, Mg(NO3)2.6H2O, is heated in a boiling tube and the following observations are made. Stage 1 Stage 2 The white solid forms a clear, colourless solution. Condensation forms around the mouth of the boiling tube and a white solid starts to form at the bottom of the tube. Stage 3 As the heating continues, the colourless solution disappears leaving a white solid. The white solid melts. Stage 4 Stage 5 A brown gas forms. Stage 6 A glowing splint reignites when it is placed in the boiling tube. Stage 7 A white solid is left in the boiling tube. (a) Explain what is happening in stages 1 and 2. D O N O T W R I T E I N T H I S A R E A (3)(b) (i) Identify the products formed in stages 5, 6 and 7. (3) Stage 5Stage 6Stage 716 (ii) Write the equation for the complete thermal decomposition of hydrated magnesium nitrate, Mg(NO3)2.6H2O. State symbols are not required. (2) *P46658A01624* D O N O T W R I T E I N T H I S A R E A D O N O T W R I T E I N T H I S A R E A<br /> (c) The chlorides of magnesium and calcium can be distinguished from each other by carrying out a flame test. (i) Describe what you would see in each test. (2) Magnesium chlorideCalcium chloride*(ii) Explain how flame colours arise in a flame test. (3)(iii) Suggest why the observations of the flame tests for magnesium chloride and calcium chloride are different. (2)(Total for Question 15 = 15 marks) TOTAL FOR SECTION B = 41 MARKS A E R A S I H T N I E T I R W T O N O D A E R A S I H T N I E T I R W T O N O D A E R A S I H T N I E T I R W T O N O D *P46658A01724* 17 Turn over<br />

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