Pearson Edexcel Level 1 /Level 2 GCSE (9-1 ) Time 1 hour 10 minutes Paper ISCO/ICH reference Combined Science PAPER 2 Higher Tier

Document Content and Description Below

Instructions • Use black ink or ball-point pen. • Fill in the boxes at the top of this page with your name, centre number and candidate number. • Answer all questions. • Answer the quest... ions in the spaces provided – there may be more space than you need. • Calculators may be used. • Any diagrams may NOT be accurately drawn, unless otherwise indicated. • You must show all your working out with your answer clearly identified at the end of your solution. Information • The total mark for this paper is 60. • The marks for each question are shown in brackets – use this as a guide as to how much time to spend on each question. • In questions marked with an asterisk (*), marks will be awarded for your ability to structure your answer logically, showing how the points that you make are related or follow on from each other where appropriate. • There is a periodic table on the back cover of the paper. Advice • Read each question carefully before you start to answer it. • Try to answer every question. • Check your answers if you have time at the end. Time 1 hour 10 minutes 1SC0/1CH Combined Science PAPER 2 Higher Tier *P69480A0220* 2  Answer ALL questions. Write your answers in the spaces provided. Some questions must be answered with a cross in a box . If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 1 Barium hydroxide reacts with dilute hydrochloric acid to form barium chloride and water. (a) The equation for the reaction is Ba(OH)2 (s) + 2HCl(aq) → BaCl 2 (aq) + 2H2 O(l) Which row of the table shows the correct state of each of the substances in the equation for the reaction? (1) A B C D barium hydroxide hydrochloric acid barium chloride water solid aqueous aqueous liquid solid liquid solid aqueous aqueous aqueous solid liquid aqueous liquid aqueous aqueous (b) A student wanted to investigate how the pH of the mixture changes as barium hydroxide is added to dilute hydrochloric acid. They followed this method. step 1 measure out 50.0cm3 of dilute hydrochloric acid into a beaker using a measuring cylinder step 2 use a glass rod to place a drop of the acid onto a piece of universal indicator paper and record the pH step 3 add 0.2g of barium hydroxide to the acid in the beaker and stir step 4 use the glass rod to place a drop of the mixture onto a new piece of universal indicator paper and record the pH again step 5 repeat steps 3–4 until there is no further change in the pH. (i) Name a piece of equipment which could be used to measure out 50.0cm3 of dilute hydrochloric acid more accurately than the measuring cylinder. (1) .................................................................................................................................................................................................................................................................................... *P69480A0320* Turn over 3  (ii) Describe how the pH of the mixture is determined when a drop of it is placed on the universal indicator paper. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (iii) In the method, universal indicator paper is used to determine the pH. Explain why litmus paper would not be a suitable indicator to use in this experiment. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... *P69480A0420* 4  (iv) Figure 1 shows the student’s results. mass of barium hydroxide in g pH of mixture 0.0 1 0.2 1 0.4 1 0.6 1 0.8 2 1.0 7 1.2 12 1.4 13 1.6 13 Figure 1 On the grid opposite: • Add suitable scales to the vertical and horizontal axes. • Plot a graph of the pH of the mixture against the mass of barium hydroxide. (3) *P69480A0520* Turn over 5  pH of the mixture mass of barium hydroxide in g (Total for Question 1 = 9 marks) *P69480A0620* 6  2 Magnesium carbonate has the formula MgCO3 . (a) Magnesium carbonate contains Mg2+ and CO3 2− ions. (i) The atomic number of magnesium is 12. What is the electronic configuration of the Mg2+ ion? (1) A 2 B 2.8 C 2.8.2 D 2.8.4 (ii) Explain why solid magnesium carbonate cannot conduct electricity but solid magnesium can. (3) ..................................................................................................................................................................................................................................................................................... ..................................................................................................................................................................................................................................................................................... ..................................................................................................................................................................................................................................................................................... ..................................................................................................................................................................................................................................................................................... ..................................................................................................................................................................................................................................................................................... ..................................................................................................................................................................................................................................................................................... (b) Calculate the percentage by mass of magnesium in magnesium carbonate, MgCO3 . (relative atomic masses: C = 12.0, O = 16.0, Mg = 24.0) (3) ..................................................................................................................................................................................................................................................................................... ..................................................................................................................................................................................................................................................................................... ..................................................................................................................................................................................................................................................................................... ..................................................................................................................................................................................................................................................................................... percentage by mass of magnesium = .............................................................. *P69480A0720* Turn over 7  (c) Magnesium carbonate reacts with dilute hydrochloric acid. Water and carbon dioxide are two of the products of the reaction. Complete the balanced equation for this reaction. (1) MgCO3 + 2HCl → .............................................................. + H2 O + CO2 (Total for Question 2 = 8 marks) *P69480A0820* 8  3 When copper sulfate solution is electrolysed using copper electrodes, the mass of each electrode changes. (a) Draw a labelled diagram to show the apparatus that can be used to electrolyse copper sulfate solution using copper electrodes. (2) (b) Before the electrolysis is carried out, the mass of each electrode is determined. Explain what should be done to the copper electrodes before their masses are determined. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (c) Figure 2 shows the results obtained from an electrolysis experiment when copper sulfate solution was electrolysed for 10 minutes. electrodes anode cathode mass of electrode before electrolysis in g 6.43 6.17 mass of electrode after electrolysis in g 5.62 6.95 change in mass in g − 0.81 + 0.78 Figure 2 *P69480A0920* Turn over 9  (i) Explain, in terms of ions, the changes in mass of the two electrodes shown in the results in Figure 2. (3) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (ii) The electrolysis was repeated using another pair of copper electrodes of the same masses. Explain a change that could be made to the electrolysis experiment to cause the mass of the cathode to increase by 2.3 [Show More]

Last updated: 1 year ago

Preview 1 out of 20 pages