Opening Paperstreak

O Level Chemistry past papers › Topics

Identification of ions and gases past paper questions

O Level Chemistry 5070 · Experimental techniques and chemical analysis. 1 Describe tests to identify the anions: (a) carbonate, CO3 2–, by reaction with dilute acid and then testing for carbon dioxide gas (b) chloride, Cl –, bromide, Br –, and iodide, I–, by acidifying with dilute nitric acid then adding aqueous silver nitrate (c) nitrate, NO3 –, by reduction with aluminium foil and aqueous sodium hydroxide and then testing for ammonia gas (d) sulfate, SO4 2–, by acidifying with dilute nitric acid then adding aqueous barium nitrate (e) sulfite, SO3 2–, by reaction with acidified aqueous potassium manganate(VII) 2 Describe tests using aqueous sodium hydroxide and aqueous ammonia to identify the aqueous cations: (a) aluminium, Al 3+ (b) ammonium, NH4 + (c) calcium, Ca2+ (d) chromium(III), Cr3+ (e) copper(II), Cu2+ (f) iron(II), Fe2+ (g) iron(III), Fe3+ (h) zinc, Zn2+ 3 Describe tests to identify the gases: (a) ammonia, NH3, using damp red litmus paper (b) carb

In Cambridge O Level Chemistry 5070, Identification of ions and gases came up in 64 of the 72 papers on Paperstreak, for about 6 marks a paper when it does. It last came up in October/November 2025.

Often set with Redox, Electrolysis, The mole and the Avogadro constant, Preparation of salts.

100 questions, newest first

  1. 5070/11/O/N/25 Question 40 · 1 mark
  2. 5070/12/O/N/25 Question 39 · 1 mark
  3. 5070/12/O/N/25 Question 40 · 1 mark
  4. 5070/21/O/N/25 Question 3 part (b) · 1 mark
  5. 5070/21/O/N/25 Question 9 parts (c) (d) · 3 marks
  6. 5070/22/O/N/25 Question 3 part (b) · 1 mark
  7. 5070/22/O/N/25 Question 9 parts (b) (c) · 3 marks
  8. 5070/41/O/N/25 Question 3 parts (a(iv)) (a(v)) (b(i)) (b(ii)) (b(iii)) (b(iv)) · 11 marks
  9. 5070/42/O/N/25 Question 3 parts (a(i)) (a(ii)) (a(iii)) (a(iv)) (b(iv)) (b(v)) · 11 marks
  10. 5070/11/M/J/25 Question 40 · 1 mark
  11. 5070/12/M/J/25 Question 40 · 1 mark
  12. 5070/21/M/J/25 Question 1 parts (b) (c) · 2 marks
  13. 5070/22/M/J/25 Question 1 parts (b) (d) · 2 marks
  14. 5070/41/M/J/25 Question 3 parts (a(ii)) (b) (c) (d) (e) (f(i)) (f(ii)) · 12 marks
  15. 5070/42/M/J/25 Question 3 parts (a(i)) (a(ii)) (b(i)) (c) (d) · 13 marks
  16. 5070/11/O/N/24 Question 40 · 1 mark
  17. 5070/12/O/N/24 Question 40 · 1 mark
  18. 5070/21/O/N/24 Question 5 part (d(i)) · 2 marks
  19. 5070/22/O/N/24 Question 5 part (e) · 2 marks
  20. 5070/41/O/N/24 Question 3 · 14 marks
  21. 5070/42/O/N/24 Question 3 · 9 marks
  22. 5070/42/O/N/24 Question 4 parts ((i)) ((ii)) ((iii)) ((iv)) · 4 marks
  23. 5070/11/M/J/24 Question 40 · 1 mark
  24. 5070/41/M/J/24 Question 3 · 14 marks
  25. 5070/42/M/J/24 Question 3 · 14 marks
  26. 5070/12/O/N/23 Question 40 · 1 mark
  27. 5070/21/O/N/23 Question 1 part (d) · 1 mark
  28. 5070/21/O/N/23 Question 4 part (c) · 2 marks
  29. 5070/22/O/N/23 Question 4 part (c) · 2 marks
  30. 5070/41/O/N/23 Question 3 parts (a(i)) (a(ii)) (a(iii)) (a(iv)) (a(v)) (a(vi)) (b(iii)) (c(i)) · 10 marks
  31. 5070/42/O/N/23 Question 3 · 14 marks
  32. 5070/12/M/J/23 Question 40 · 1 mark
  33. 5070/21/M/J/23 Question 2 part (c) · 1 mark
  34. 5070/41/M/J/23 Question 3 · 0 marks
  35. 5070/41/M/J/23 Question 4 · 20 marks
  36. 5070/42/M/J/23 Question 3 parts (a(i)) (a(iii)) (b(i)) (b(iii)) (b(iv)) (b(v)) · 10 marks
  37. 5070/11/O/N/22 Question 3 · 1 mark
  38. 5070/12/O/N/22 Question 3 · 1 mark
  39. 5070/21/O/N/22 Question 5 part (d) · 3 marks
  40. 5070/22/O/N/22 Question 5 part (b) · 2 marks
  41. 5070/41/O/N/22 Question 2 part (b(i)) · 2 marks
  42. 5070/41/O/N/22 Question 3 part (b(i)) · 2 marks
  43. 5070/41/O/N/22 Question 6 · 9 marks
  44. 5070/42/O/N/22 Question 2 part (c) · 2 marks
  45. 5070/42/O/N/22 Question 3 part (c(i)) · 2 marks
  46. 5070/42/O/N/22 Question 6 · 9 marks
  47. 5070/11/M/J/22 Question 3 · 1 mark
  48. 5070/12/M/J/22 Question 3 · 1 mark
  49. 5070/21/M/J/22 Question 1 parts (a) (b) (c) · 3 marks
  50. 5070/21/M/J/22 Question 5 part (b(ii)) · 2 marks
  51. 5070/22/M/J/22 Question 6 part (b) · 2 marks
  52. 5070/41/M/J/22 Question 2 parts (b(i)) (b(ii)) (c) · 13 marks
  53. 5070/11/O/N/21 Question 5 · 1 mark
  54. 5070/11/O/N/21 Question 6 · 1 mark
  55. 5070/12/O/N/21 Question 5 · 1 mark
  56. 5070/12/O/N/21 Question 6 · 1 mark
  57. 5070/21/O/N/21 Question 2 part (d) · 2 marks
  58. 5070/21/O/N/21 Question 5 part (c) · 1 mark
  59. 5070/21/O/N/21 Question 9 part (d) · 1 mark
  60. 5070/22/O/N/21 Question 1 parts (b) (d) · 2 marks
  61. 5070/22/O/N/21 Question 2 part (b) · 2 marks
  62. 5070/22/O/N/21 Question 5 part (b) · 1 mark
  63. 5070/41/O/N/21 Question 2 part (a(i)) · 1 mark
  64. 5070/41/O/N/21 Question 3 · 7 marks
  65. 5070/41/O/N/21 Question 4 part (b) · 1 mark
  66. 5070/41/O/N/21 Question 5 parts (b(i)) (b(ii)) (c(i)) (c(ii)) (c(iii)) (d) · 8 marks
  67. 5070/42/O/N/21 Question 2 part (a(i)) · 1 mark
  68. 5070/42/O/N/21 Question 3 · 7 marks
  69. 5070/42/O/N/21 Question 5 parts (b(i)) (b(ii)) (c(i)) (c(ii)) (c(iii)) (d) · 8 marks
  70. 5070/11/M/J/21 Question 4 · 1 mark
  71. 5070/11/M/J/21 Question 5 · 1 mark
  72. 5070/12/M/J/21 Question 4 · 1 mark
  73. 5070/12/M/J/21 Question 5 · 1 mark
  74. 5070/21/M/J/21 Question 8 part (f) · 1 mark
  75. 5070/41/M/J/21 Question 3 · 11 marks
  76. 5070/42/M/J/21 Question 2 · 12 marks
  77. 5070/42/M/J/21 Question 5 part (a(ii)) · 2 marks
  78. 5070/11/O/N/20 Question 5 · 1 mark
  79. 5070/11/O/N/20 Question 6 · 1 mark
  80. 5070/12/O/N/20 Question 5 · 1 mark
  81. 5070/12/O/N/20 Question 6 · 1 mark
  82. 5070/21/O/N/20 Question 1 part (a) · 1 mark
  83. 5070/21/O/N/20 Question 3 part (b) · 2 marks
  84. 5070/22/O/N/20 Question 3 part (b(i)) · 2 marks
  85. 5070/41/O/N/20 Question 2 part (a) · 1 mark
  86. 5070/41/O/N/20 Question 5 parts (b(i)) (b(ii)) (b(iii)) (c) · 7 marks
  87. 5070/42/O/N/20 Question 1 part (b) · 1 mark
  88. 5070/42/O/N/20 Question 2 part (a) · 1 mark
  89. 5070/42/O/N/20 Question 5 parts (b(i)) (b(ii)) (c(i)) (c(ii)) (c(iii)) (d) · 10 marks
  90. 5070/11/M/J/20 Question 4 · 1 mark
  91. 5070/11/M/J/20 Question 15 · 1 mark
  92. 5070/12/M/J/20 Question 4 · 1 mark
  93. 5070/21/M/J/20 Question 9 part (e) · 2 marks
  94. 5070/22/M/J/20 Question 1 part (b) · 1 mark
  95. 5070/22/M/J/20 Question 8 part (e) · 2 marks
  96. 5070/22/M/J/20 Question 9 part (f) · 2 marks
  97. 5070/22/M/J/20 Question 10 part (c(i)) · 1 mark
  98. 5070/41/M/J/20 Question 1 part (b) · 1 mark
  99. 5070/41/M/J/20 Question 4 parts (a(i)) (a(ii)) (c) · 11 marks
  100. 5070/42/M/J/20 Question 2 · 10 marks

More in Experimental techniques and chemical analysis: Experimental design, Acid–base titrations, Chromatography, Separation and purification.

Questions and mark schemes from Cambridge International past papers. Paperstreak isn't affiliated with Cambridge.