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Acid/Base Equilibria · CAPE Chemistry Unit 1

150 past-paper questions on Acid/Base Equilibria, part of Kinetics and Equilibria, from every CAPE Chemistry Unit 1 paper on Quelpr.

Practise Acid/Base Equilibria
  1. 4(a)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1Identify ANY TWO functional groups that are present in lactic acid or alanine.
  2. 4(b)(i)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1Distinguish between electrophiles and nucleophiles.
  3. 4(b)(ii)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1Distinguish between homolytic and heterolytic bond fission.
  4. 4(c)(ii)a)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 1Outline the bond-breaking step involved in the reaction of 2-chloro-2-methylpropane with sodium hydroxide.
  5. 4(c)(ii)b)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 1Outline the bond-forming step involved in the reaction of 2-chloro-2-methylpropane with sodium hydroxide.
  6. 5(c)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 1Nitrobenzene reacts with tin and concentrated hydrochloric acid. State the product formed.
  7. 6(a)(i)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 1State the meaning of the term pKa.
  8. 6(a)(ii)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1Explain the significance of the given pKa values.
  9. 6(a)(iii)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1Describe the features of EACH of the organic molecules that account for the difference in pKa values.
  10. 6(b)(i)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1Give the displayed formula of L-threonine in an acidic solution.
  11. 8(a)(i)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 1Describe the property of the nuclei that allows them to be detected in NMR analysis.
  12. 8(a)(ii)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 1Give the symbols for the TWO main nuclei found in organic molecules that are detected by NMR analysis.
  13. 8(a)(iii)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1State the changes that occur in the molecules of a sample when subjected first to an external magnetic field and then to radio wave signals.
  14. 8(b)(i)3 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1Which TWO functional groupings are indicated by the chemical shift values? Explain your reasoning.
  15. 8(b)(ii)3 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1Suggest a structure for the organic compound C₉H₁₀O.
  16. 9(a)(i)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 1Suggest a type of solvent that could be used to isolate an organic product from an aqueous reaction mixture.
  17. 9(a)(ii)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1Describe TWO properties the solvent should have for this extraction method to work.
  18. 9(a)(iii)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1Briefly explain ONE principle on which solvent extraction is based.
  19. 9(b)(i)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 1Suggest a method that would be suitable to extract natural organic compounds from plant material.
  20. 9(b)(ii)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1Give TWO features of the extraction method suggested in (b)(i) that allow the stated objectives to be achieved.
  21. 9(b)(iii)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 1Explain why the features mentioned in (b)(ii) are essential.
  22. 2(a)4 marks· CAPE Chemistry Unit 1 · 2005 · Paper 2Complete the observations and inferences in Table 1 for tests (i) through (iv).
  23. 2(b)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 2Suggest a displayed formula for Z, given its relative molecular mass is 46.
  24. 2(c)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 2Write the formula of the organic ester product formed in test (a)(ii).
  25. 2(d)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 2Suggest a reagent to identify the gas liberated in test (a)(iv) with phosphorus pentachloride and state the expected observation.
  26. 2(e)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 2Suggest the reagent and conditions required to regenerate Z from the ester produced in test (a)(ii).
  27. 3(c)3 marks· CAPE Chemistry Unit 1 · 2005 · Paper 2Select the most suitable indicator from Table 2 for the titration shown in Figure 1, explaining your choice using the titration curve.
  28. 7(a)(i)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 2Explain the term stereoisomerism.
  29. 7(a)(ii)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 2Explain the term structural isomerism.
  30. 7(b)(i)6 marks· CAPE Chemistry Unit 1 · 2005 · Paper 2Classify each given pair of structures (a, b, and c) as structural isomers, geometric isomers, or the same compound, providing reasons.
  31. 7(b)(ii)3 marks· CAPE Chemistry Unit 1 · 2005 · Paper 2Provide the systematic IUPAC names for each isomer shown in (b)(i) parts a) and b).
  32. 7(c)(ii)2 marks· CAPE Chemistry Unit 1 · 2005 · Paper 2Deduce the structural formulae of the two isomers A and B.
  33. 7(c)(iii)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 2State the specific type of isomerism displayed by A and B.
  34. 7(e)(i)3 marks· CAPE Chemistry Unit 1 · 2005 · Paper 2Draw the displayed structure of the repeating unit of nylon 6,6.
  35. 7(e)(ii)1 mark· CAPE Chemistry Unit 1 · 2005 · Paper 2Identify the common structural feature present in both proteins and nylon 6,6.
  36. 2(a)(i)2 marks· CAPE Chemistry Unit 1 · May/June 2019 · Paper 2Using the Bronsted-Lowry theory, differentiate between a 'strong acid' and a 'weak acid'.
  37. 2(a)(ii)2 marks· CAPE Chemistry Unit 1 · May/June 2019 · Paper 2Carbonic acid forms a weak acidic solution in water. Write an equation to represent the change when carbonic acid is dissolved in water.
  38. 2(a)(iii)2 marks· CAPE Chemistry Unit 1 · May/June 2019 · Paper 2State TWO weak acids other than carbonic acid.
  39. 2(b)(i)2 marks· CAPE Chemistry Unit 1 · May/June 2019 · Paper 2Define EACH of the terms pH and pKa.
  40. 2(b)(ii)2 marks· CAPE Chemistry Unit 1 · May/June 2019 · Paper 2Calculate the pH of a 0.100 mol dm^-3 aqueous solution of carbonic acid (Ka of carbonic acid = 4.5 x 10^-7 at the experimental temperature).
  41. 2(b)(iii)3 marks· CAPE Chemistry Unit 1 · May/June 2019 · Paper 2Determine the pKa of carbonic acid and compare its strength with an aqueous solution of hydrogen sulfide (Ka of hydrogen sulfide = 8.9 x 10^-8).
  42. 2(b)(iv)3 marks· CAPE Chemistry Unit 1 · May/June 2019 · Paper 2Sketch a labelled graph to show the pH changes which occur during the titration of 25 cm^3 of 0.10 mol dm^-3 carbonic acid with 0.10 mol dm^-3 of sodium hydroxide solution.
  43. 2(a)(i)1 mark· CAPE Chemistry Unit 1 · May/June 2022 · Paper 2Define the term 'pH'.
  44. 2(a)(ii)2 marks· CAPE Chemistry Unit 1 · May/June 2022 · Paper 2Calculate the hydrogen ion concentration of the colourless liquid with pH 4.2.
  45. 2(a)(iii)4 marks· CAPE Chemistry Unit 1 · May/June 2022 · Paper 2Twenty cm^3 of a solution with the same pH as the extracted liquid is titrated with 1 x 10^-4 mol dm^-3 aqueous sodium hydroxide. Sketch the titration curve that will be obtained.
  46. 2(a)(iv)3 marks· CAPE Chemistry Unit 1 · May/June 2022 · Paper 2Using Table 3 showing pH ranges of indicators, suggest with reasons which indicator is the most suitable for use in the titration in (iii).
  47. 2(b)(i)2 marks· CAPE Chemistry Unit 1 · May/June 2023 · Paper 2State the difference in behaviour between a strong acid and a strong base according to the Brønsted-Lowry Theory.
  48. 2(b)(ii)1 mark· CAPE Chemistry Unit 1 · May/June 2023 · Paper 2Write the reaction for the dissociation of CH₃COOH.
  49. 2(b)(iii)6 marks· CAPE Chemistry Unit 1 · May/June 2023 · Paper 2Complete Table 2, using the variable x to generate expressions for the equilibrium concentrations of the reaction components for a 0.30 M solution of CH₃COOH.
  50. 2(b)(iv)1 mark· CAPE Chemistry Unit 1 · May/June 2023 · Paper 2Generate an expression for K_a for this reaction using equilibrium expressions obtained in (b)(iii).
  51. 2(b)(v)3 marks· CAPE Chemistry Unit 1 · May/June 2023 · Paper 2Calculate the pH of a 0.30 M solution of CH₃COOH at 25 °C, if x is 0.0023 M.
  52. 2(c)1 mark· CAPE Chemistry Unit 1 · May/June 2026 · Paper 2Define the term 'acid' using the Bronsted-Lowry theory.
  53. 2(d)(i)2 marks· CAPE Chemistry Unit 1 · May/June 2026 · Paper 2Write the equation for the dissociation of hydrofluoric acid in aqueous solution.
  54. 2(d)(ii)1 mark· CAPE Chemistry Unit 1 · May/June 2026 · Paper 2Write the expression for the dissociation constant for hydrofluoric acid.
  55. 2(d)(iii)3 marks· CAPE Chemistry Unit 1 · May/June 2026 · Paper 2Calculate the pH of 0.10 mol dm^-3 hydrofluoric acid.
  56. 2(d)(iv)3 marks· CAPE Chemistry Unit 1 · May/June 2026 · Paper 2A student performs a titration, adding 0.10 mol dm^-3 sulfuric acid to 25 cm³ of 0.10 mol dm^-3 sodium hydroxide solution. Using the axes in Figure 1, sketch a graph to show the changes in pH which occur during the…
  57. 2(a)(i)1 mark· Chemistry · Unit 1 Q2 2(a)(i)Explain what is meant by the term 'weak acid'.
  58. 2(a)(i)1 mark· Chemistry · Unit 1 Q2 2(a)(i)State the Brønsted-Lowry theory of acids and bases.
  59. 2(a)(i)4 marks· Chemistry · Unit 1 Q2 2(a)(i)Complete Table 1, row (i) for the observation when an alkaline solution of silver nitrate is added to a few cm³ of X and the mixture is warmed, given the inference is Aldehyde.
  60. 2(a)(i)1 mark· Chemistry · Unit 1 Q2 2(a)(i)Define EACH of the following terms: Weak acid
  61. 2(a)(ii)2 marks· Chemistry · Unit 1 Q2 2(a)(ii)Distinguish between a 'strong acid' and a 'weak acid'.
  62. 2(a)(ii)1 mark· Chemistry · Unit 1 Q2 2(a)(ii)Write an expression for the dissociation constant, Kₐ, of methanoic acid.
  63. 2(a)(ii)2 marks· Chemistry · Unit 1 Q2 2(a)(ii)Define EACH of the following terms: Kₐ
  64. 2(a)(ii)4 marks· Chemistry · Unit 1 Q2 2(a)(ii)Complete Table 1, row (ii) for the observation when iodine and X are warmed with some NaOH in a test tube, given the inference is Methylketone.
  65. 2(a)(iii)4 marks· Chemistry · Unit 1 Q2 2(a)(iii)Complete Table 1, row (iii) for the observation when X is added to a few cm³ of bromine in tetrachloromethane, given the inference is Alkene.
  66. 2(a)(iv)4 marks· Chemistry · Unit 1 Q2 2(a)(iv)Complete Table 1, row (iv) for the inference when X is added to dilute HCl and white crystals are produced.
  67. 2(a)(v)1 mark· Chemistry · Unit 1 Q2 2(a)(v)Suggest a value for the pH of a solution of X.
  68. 2(a)(vi)1 mark· Chemistry · Unit 1 Q2 2(a)(vi)The mass spectrum of X reveals that it has a RMM of 203. A prominent peak is also observed in the mass spectrum at m/z 77. Use this information and the results of your chemical analysis as recorded in Table 1 above to…
  69. 2(b)(i)2 marks· Chemistry · Unit 1 Q2 2(b)(i)Write an equation to represent the dissociation of carbonic acid in aqueous solution.
  70. 2(b)(i)2 marks· Chemistry · Unit 1 Q2 2(b)(i)Using Bronsted-Lowry theory, explain what is meant by a strong base.
  71. 2(b)(i)2 marks· Chemistry · Unit 1 Q2 2(b)(i)In the space below, sketch the curve which is expected to illustrate the changes that take place during titration.
  72. 2(b)(i)3 marks· Chemistry · Unit 1 Q2 2(b)(i)Complete Table 2, row (i) for the inference when Acidified KMnO4 is added to a few cm³ of Y, and the mixture is warmed, and the observation is colour changes from purple to colourless.
  73. 2(b)(ii)2 marks· Chemistry · Unit 1 Q2 2(b)(ii)Calculate the pH of the standard NaOH solution.
  74. 2(b)(ii)1 mark· Chemistry · Unit 1 Q2 2(b)(ii)Write the Kₐ expression for the reaction in (b) (i).
  75. 2(b)(ii)2 marks· Chemistry · Unit 1 Q2 2(b)(ii)Suggest an indicator, giving a reason for your choice.
  76. 2(b)(ii)3 marks· Chemistry · Unit 1 Q2 2(b)(ii)Complete Table 2, row (ii) for the test when the observation is white precipitate produced, and the inference is Phenol present.
  77. 2(b)(iii)2 marks· Chemistry · Unit 1 Q2 2(b)(iii)The concentration of methanoic acid in Solution Y is found to be 6.0 x 10⁻³ mol dm⁻³. Calculate the pH of Solution Y.
  78. 2(b)(iii)4 marks· Chemistry · Unit 1 Q2 2(b)(iii)Calculate the pH of a 0.100 mol dm⁻³ aqueous solution of carbonic acid. (Kₐ = 4.5 × 10⁻⁷ mol dm⁻³ at 25 °C.)
  79. 2(b)(iii)3 marks· Chemistry · Unit 1 Q2 2(b)(iii)Complete Table 2, row (iii) for the test when the observation is gas evolves which forms white fumes with NH3(g), and the inference is Carboxylic acid group.
  80. 2(b)(iv)1 mark· Chemistry · Unit 1 Q2 2(b)(iv)Suggest a suitable indicator for the titration between methanoic acid and sodium hydroxide.
  81. 2(b)(iv)1 mark· Chemistry · Unit 1 Q2 2(b)(iv)The molecular formula for Y is found to be C9H10O4. Suggest a structural formula for Y.
  82. 2(b)(v)4 marks· Chemistry · Unit 1 Q2 2(b)(v)Sketch a graph to illustrate the changes in pH that take place during the titration.
  83. 3(a)3 marks· Chemistry · Unit 1 Q3 3(a)Identify EACH of the processes 1, 2 and 3 in Figure 1.
  84. 3(b)(i)3 marks· Chemistry · Unit 1 Q3 3(b)(i)Suggest the name of Solvent A and explain why the solvent suggested is suitable.
  85. 3(b)(ii)1 mark· Chemistry · Unit 1 Q3 3(b)(ii)Describe Mixture B
  86. 3(c)(i)1 mark· Chemistry · Unit 1 Q3 3(c)(i)Suggest a suitable piece of equipment which could be used to obtain the extracted product
  87. 3(c)(ii)1 mark· Chemistry · Unit 1 Q3 3(c)(ii)Suggest a suitable piece of equipment which could be used to obtain the dry crystals.
  88. 3(d)1 mark· Chemistry · Unit 1 Q3 3(d)Mixture B shows some discolouration and an additional step is required before Process 2. Name the purifying agent necessary in this step.
  89. 4(a)(i)1 mark· Chemistry · Unit 1 Q4 4(a)(i)Which of the functional groups present in aspartame would react with ethanol?
  90. 4(a)(ii)2 marks· Chemistry · Unit 1 Q4 4(a)(ii)Which of the functional groups present in aspartame would react with dilute hydrochloric acid?
  91. 4(a)(iii)1 mark· Chemistry · Unit 1 Q4 4(a)(iii)Which of the functional groups present in aspartame would react with ethanoyl chloride?
  92. 4(b)1 mark· Chemistry · Unit 1 Q4 4(b)Name the OTHER chemical that is required for the reaction with ethanol to occur.
  93. 4(b)(i)a)3 marks· Chemistry · Unit 1 Q4 4(b)(i)a)Write an expression for EACH of the following terms: Ka
  94. 4(b)(i)b)3 marks· Chemistry · Unit 1 Q4 4(b)(i)b)Write an expression for EACH of the following terms: pKa
  95. 4(b)(i)c)3 marks· Chemistry · Unit 1 Q4 4(b)(i)c)Write an expression for EACH of the following terms: pH
  96. 4(b)(ii)2 marks· Chemistry · Unit 1 Q4 4(b)(ii)Given that Ka for acid HP is 3.0 x 10-5 mol dm-³, predict the relative size of Ka for a stronger acid HQ. Explain your reasoning.
  97. 4(c)(i)1 mark· Chemistry · Unit 1 Q4 4(c)(i)Draw the structural formula of B.
  98. 4(c)(ii)2 marks· Chemistry · Unit 1 Q4 4(c)(ii)State the reagents and conditions required for the conversion of B to C.
  99. 4(c)(iii)2 marks· Chemistry · Unit 1 Q4 4(c)(iii)State ONE physical property that is characteristic of BOTH Compound C and that obtained in the reaction described in (b) above. Explain your answer.
  100. 5(a)2 marks· Chemistry · Unit 1 Q5 5(a)State TWO reasons why carbon can form straight chains and rings.
  101. 5(a)3 marks· Chemistry · Unit 1 Q5 5(a)Account for the observations in the statement below: Pure water is a poor conductor of electricity whereas water in the presence of a trace of H⁺(aq) is a good conductor.
  102. 5(a)(i)2 marks· Chemistry · Unit 1 Q5 5(a)(i)Define EACH of the following terms: pH
  103. 5(a)(i)2 marks· Chemistry · Unit 1 Q5 5(a)(i)With reference to the Bronsted-Lowry theory, explain EACH of the following: Weak acid
  104. 5(a)(ii)1 mark· Chemistry · Unit 1 Q5 5(a)(ii)With reference to the Bronsted-Lowry theory, explain EACH of the following: Strong acid
  105. 5(b)1 mark· Chemistry · Unit 1 Q5 5(b)Write the molecular formula of Dopa.
  106. 5(b)2 marks· Chemistry · Unit 1 Q5 5(b)Describe the significance of pH (- log [H⁺]) and Kₐ (acid dissociation constant) values.
  107. 5(b)(i)3 marks· Chemistry · Unit 1 Q5 5(b)(i)Derive the relationship for the ionic product of water, Kᵥ.
  108. 5(b)(i)1 mark· Chemistry · Unit 1 Q5 5(b)(i)Write an expression for the acid dissociation constant (Ka) of ethanoic acid.
  109. 5(b)(ii)3 marks· Chemistry · Unit 1 Q5 5(b)(ii)State how the value of Kᵥ varies with temperature.
  110. 5(b)(ii)4 marks· Chemistry · Unit 1 Q5 5(b)(ii)Calculate the equilibrium concentration of ethanoic acid in a solution that has a pH of 5.
  111. 5(c)(i)1 mark· Chemistry · Unit 1 Q5 5(c)(i)Define the term 'isomerism'.
  112. 5(c)(i)4 marks· Chemistry · Unit 1 Q5 5(c)(i)Calculate the pH of EACH of the solutions A, B and C, given that their concentrations are as shown in the table below.
  113. 5(c)(ii)2 marks· Chemistry · Unit 1 Q5 5(c)(ii)State TWO types of isomerism which can be exhibited by a molecule with formula A.
  114. 5(c)(ii)4 marks· Chemistry · Unit 1 Q5 5(c)(ii)Place the solutions A, B and C in 5 (c) (i) on a pH scale relative to the pH of pure water.
  115. 5(c)(iii)4 marks· Chemistry · Unit 1 Q5 5(c)(iii)Draw the full structural formulae of TWO isomers for each type of isomerism stated in (c)(ii) on page 8.
  116. 5(d)(i)1 mark· Chemistry · Unit 1 Q5 5(d)(i)Define the term 'Brönsted - Lowry base'.
  117. 5(d)(ii)2 marks· Chemistry · Unit 1 Q5 5(d)(ii)Identify TWO bases in Equation 2.
  118. 5(e)3 marks· Chemistry · Unit 1 Q5 5(e)Calculate the pH of a 0.05 mol dm-3 solution of Ba(OH)2.
  119. 6(a)(i)1 mark· Chemistry · Unit 1 Q6 6(a)(i)How many monomer units are present in this portion of the macromolecule?
  120. 6(a)(i)6 marks· Chemistry · Unit 1 Q6 6(a)(i)Describe EACH of the following terms, using appropriate examples: Homolytic bond fission
  121. 6(a)(ii)2 marks· Chemistry · Unit 1 Q6 6(a)(ii)Draw the displayed structure of two monomers used to make A.
  122. 6(a)(ii)6 marks· Chemistry · Unit 1 Q6 6(a)(ii)Describe EACH of the following terms, using appropriate examples: Inductive effect
  123. 6(b)2 marks· Chemistry · Unit 1 Q6 6(b)To what class of compounds do the monomers and macromolecule, A, belong?
  124. 6(b)(i)4 marks· Chemistry · Unit 1 Q6 6(b)(i)State TWO types of reaction mechanisms which citral will undergo, identifying the functional group involved in EACH case.
  125. 6(b)(ii)8 marks· Chemistry · Unit 1 Q6 6(b)(ii)With the use of simple molecules containing the functional groups identified in (b) (i), explain the steps involved in EACH of the mechanisms mentioned in (b) (i).
  126. 6(c)2 marks· Chemistry · Unit 1 Q6 6(c)Identify the mechanism and draw the product of this reaction.
  127. 6(c)(i)1 mark· Chemistry · Unit 1 Q6 6(c)(i)Name the type of reaction that occurs when nylon 6.6 or A is boiled with concentrated hydrochloric acid.
  128. 6(c)(ii)1 mark· Chemistry · Unit 1 Q6 6(c)(ii)Copy the structure of A and use it to illustrate the changes that occur during the reaction described in (c)(i) above.
  129. 6(c)(iii)1 mark· Chemistry · Unit 1 Q6 6(c)(iii)Draw the fully displayed structure of ONE product of the reaction described in (c)(i) above.
  130. 6(d)2 marks· Chemistry · Unit 1 Q6 6(d)State ONE common structural feature and ONE different structural feature in nylon 6.6 and A.
  131. 7(a)(i)4 marks· Chemistry · Unit 1 Q7 7(a)(i)For the reaction sequence given above, state the reagents and conditions needed for Reactions I and II.
  132. 7(a)(ii)2 marks· Chemistry · Unit 1 Q7 7(a)(ii)Identify ONE OTHER product that could be obtained in Reaction I by changing the conditions. State the condition(s) needed.
  133. 7(b)(i)8 marks· Chemistry · Unit 1 Q7 7(b)(i)Explain the differences in basic character of A, ammonia and amphetamine. In your explanation make reference to the molecular features of each molecule. State the order of INCREASING basic character of the three…
  134. 7(b)(ii)1 mark· Chemistry · Unit 1 Q7 7(b)(ii)Write an equation to show the basic nature of any ONE of the above substances.
  135. 7(b)(iii)2 marks· Chemistry · Unit 1 Q7 7(b)(iii)The pKa of A is 9.62. Suggest how the pKa of amphetamine and ammonia should vary relative to that of A.
  136. 7(c)(i)2 marks· Chemistry · Unit 1 Q7 7(c)(i)Predict pH values for difluoroethanoic acid and dibromoethanoic acid.
  137. 7(c)(ii)1 mark· Chemistry · Unit 1 Q7 7(c)(ii)Would benzoic acid be a stronger or weaker acid than ethanoic acid?
  138. 8(a)(i)1 mark· Chemistry · Unit 1 Q8 8(a)(i)What is meant by retention time as applied to gas liquid chromatography (GLC)?
  139. 8(a)(ii)2 marks· Chemistry · Unit 1 Q8 8(a)(ii)Distinguish between a stationary phase and a mobile phase used in chromatography.
  140. 8(a)(iii)2 marks· Chemistry · Unit 1 Q8 8(a)(iii)Give ONE example EACH of commonly used stationary and mobile phases in GLC.
  141. 8(b)(i)2 marks· Chemistry · Unit 1 Q8 8(b)(i)Calculate the Rᶠ values for the TWO samples.
  142. 8(b)(ii)3 marks· Chemistry · Unit 1 Q8 8(b)(ii)Deduce whether the same red dye is used to make both types of ink. Give TWO reasons for your answer.
  143. 9(a)3 marks· Chemistry · Unit 1 Q9 9(a)Infra red (IR) spectroscopy is widely used to determine the structure of molecules. State the principles upon which infra red (IR) spectroscopy is based.
  144. 9(c)1 mark· Chemistry · Unit 1 Q9 9(c)Explain how the IR spectra may be used to distinguish between functional groups in organic compounds.
  145. 9(e)1 mark· Chemistry · Unit 1 Q9 9(e)Suggest ONE reason why HCl has only one peak in its IR spectrum.
  146. 9(f)(i)1 mark· Chemistry · Unit 1 Q9 9(f)(i)Give ONE reason why the monochromator and sample cell are not constructed of glass or quartz.
  147. 9(f)(ii)1 mark· Chemistry · Unit 1 Q9 9(f)(ii)What material may be used instead of quartz or glass?
  148. 211 mark· Chemistry · Unit 1 Q21 21Which of the acids in the table below is the WEAKEST?
  149. 231 mark· Chemistry · Unit 1 Q23 23The H⁺(aq) concentration of the juice in mol dm⁻³ is
  150. 441 mark· Chemistry · Unit 1 Q44 44Which of the following compounds would produce the LOWEST pH when 0.5 mol of it is bubbled into 1 litre of water?

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