Level 3 Applied Science UNIT 1: Principles & Applications of Science I CHEMISTRY SECTION Questions Booklet Name:.. Teacher:.. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 1
1. State the relative mass and charge for protons, neutrons and electrons. 2. Where is most of the mass in an atom located? 3. How many electrons are found in the first and second shells of an atom? 4. In which part of an atom are neutrons found? 5. State what is meant by the terms: (i) atomic number (ii) mass number 6. What is the elemental symbol for fluorine? 7. Calculate the number of protons, neutrons and electrons in the neutral element that has an atomic number of 34 and mass number of 79 for one of its pure isotopes. 8. Si has isotopes with a mass number of 28 and 29, yet the relative atomic mass is 28.1. What does this tell you about the relative amounts of each isotope in a sample of Si found in nature? Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 2
9. Complete the following table: Pure Isotope Atomic no. (protons) Mass no. (protons + neutrons) No. of electrons No. of neutrons R.A.M in periodic table 16 O 32 S 10 B 24 Mg 14 N 15 N 12 C 13 C 14 C 10. State what is meant by the term relative atomic mass. 11. What is the difference between two isotopes of the same element? 12. Explain why 14 N and 35 Cl are not isotopes, but 14 N and 15 N are isotopes.... 13. Explain why 14 N and 15 N have the same chemical properties.... 14. What is the standard used when weighing atomic masses? Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 3
15. Calculate the relative atomic mass, Ar, of the following. (a) A sample of boron containing 18.7% 10 B and 81.3% 11 B. Give your answer to 3 significant figures. Answer =... (b) A sample of magnesium containing 78.6% 24 Mg, 10.1% 25 Mg and 11.3% 26 Mg. Give your answer to 4 significant figures. Answer =... (c) A sample of lead containing 1.55% 204 Pb, 23.6% 206 Pb, 22.6% 207 Pb and 52.3% 208 Pb. Give your answer to 4 significant figures. Answer =... (d) A sample of iron containing 5.8% 54 Fe, 91.6% 56 Fe, 2.2% 57 Fe and 0.33% 58 Fe. Give your answer to 3 significant figures. Answer =... (e) A sample of zinc containing 48.9% 64 Zn, 27.8% 66 Zn, 4.1% 67 Zn, 18.6% 68 Zn and 0.62% 70 Zn. Give your answer to 3 significant figures. 16. Explain why Mg and Ca have similar chemical properties. Answer =... 17. Identify the element in: (i) Group 3, Period 3.. (ii) Group 8, Period 1.. (iii) Group 7, Period 5.. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 4
18. Explain how the elements are arranged in the Periodic Table 19. Explain what is meant by the term Periodicity. Use examples in your answer. 20. Compare and explain the atomic radius of F and Cl. 21. Compare and explain the atomic radius of Li and F. 22. Explain what is meant by cation and anion. 23. Explain the octet rule. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 5
24. Predict the charges on the ions in the table below Mg 2+ F N Al P Br Sr O Cs K Li Cl S Ca Rb Ba I Cu Fe Mn 25. Draw diagrams to show the formation of the following ions: i) Mg to Mg 2+ ii) K to K + iii) O to O 2-26. Complete the following table Atom/Ion Atomic no. Mass no. No. of protons No. of neutrons No. of electrons 14 N 3-16 O 2-23 Na + 27 Al 3+ Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 6
27. Compare, and explain, the radius of Ca with its cation. 28. Compare, and explain, the radius of P with its anion. 29. Explain what is meant by the term isoelectronic. 30. Identify any ions that are isoelectronic with Ca. 31. Explain what is meant by the term first ionisation energy. 32. Explain why energy is required to remove electrons from atoms. Is this shown by a positive or negative sign? 33. Write equations to show the following ionisation energies (i) first for Li:.. (ii) third for Ga:... (iii) ninth for Na:. (iv) tenth for Al:.. (v) sixth for C:. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 7
34. Explain why the first ionisation energy for Be is greater than the first for Li. 35. Explain why the first ionisation energy for Na is less than the first for Li. 36. Explain what is meant by first electron affinity. 37. Write equations for the first and second electron affinities for: (i) O. (ii) N (iii) P... (iv) S Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 8
38. Explain why energy is released for the first electron affinity but energy is required for the second electron affinity. Is this shown by a positive or negative sign? 39. Explain why less energy is released for the first electron affinity of Br than the first for Cl. 40. Explain why less energy is released for the first electron affinity of Se than the first for Br. 41. State, and explain, whether the following show ionic, covalent or metallic bonding: (i) Ca.. (ii) O2.. (iii) NaBr.. (iv) NH3.. (v) Mg.. (vi) MgCl2.. (vii) CO2.. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 9
(viii) CH4.. (iv) AlCl3.. 42. Complete the table below Name of ionic compound Cross-over working Sodium fluoride Magnesium fluoride Aluminium chloride Magnesium phosphide Formula of ionic compound 43. Draw dot and cross diagrams for the following and also calculate the relative formula mass: (i) sodium fluoride, NaF (ii) magnesium chloride, MgCl2 (iii) aluminium oxide, Al2O3 R.F.M (iv) Barium oxide, BaO R.F.M (v) Calcium sulphide, CaS R.F.M (vi) Barium nitride, Ba3N2 R.F.M R.F.M R.F.M Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 10
44. What two factors affect the strength of an ionic bond? Explain your answer. 45. Draw dot & cross diagrams for the following and calculate the relative molecular mass (i) hydrogen, H2 (ii) chlorine, Cl2 (iii) methane, CH4 R.M.M (iv) oxygen, O2 R.M.M (v) nitrogen, N2 R.M.M R.M.M (vi) H3O + (formed from the reaction of H 2O with H + ) R.M.M R.F.M Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 11
46. State what is meant by a dative covalent bond, using a dot & cross diagram of the ammonium ion as your example. 47. Draw a 3D diagram of methane. State the name of the shape and the bond angle. 48. Draw dot & cross diagrams for Cl2 and CO2. Use these diagrams to compare the strength and length of the bonds in Cl2 and in CO2. 49. State what is meant by the term metallic bonding, using a labelled diagram to illustrate your answer. You should also give examples of substances which have metallic bonding. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 12
50. Explain the following properties of metals: (i) conduction of heat and electricity (ii) malleability and ductility. 51. State what is meant by the term electronegativity. Explain the trends in electronegativity values in the periodic Table. 52. Show any dipoles on the examples below and state whether the bond is polar or non-polar: H F C Cl O H S F N H H Cl C O N O Cl F Br Br 53. Explain what factors affect the electronegativity of an element. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 13
54. Explain how polar and non-polar molecules arise. 55. State what is meant by the term intermolecular force. List the three types of intermolecular forces in order of increasing strength. How do intermolecular forces compare with ionic, covalent and metallic bonds? 56. Explain how temporary dipole-induced dipole forces arise. 57. Explain why the boiling point of the noble gases increases as you go down the group 8. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 14
58. Draw diagrams showing hydrogen bonding between: (i) neighbouring NH3 molecules (ii) neighbouring HF molecules (iii) one molecule of water and one molecule of ammonia. 59. Identify the intermolecular forces present in the following (i) O2 (ii) N2.. (iii) F2.. (iv) HF. (v) CH3CH2NH2.... (vi) CH3CH2OH.. (vii) HCl. (viii) H2S. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 15
60. Explain why ICl has a higher boiling point than Cl2. 61. Explain why H2O has a higher boiling point than H2. 62. Explain why H2O has a higher boiling point than HCl. 63. Explain why O2 has a lower melting point than Li. 64. Explain why Cl2 has a lower melting point than Si. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 16
65. Explain why Al has a higher melting point than Mg, which has a higher melting point than Na. 66. Explain why S has a higher melting point than P, which has a higher melting point than Cl, which has a higher melting point than Ar. 67. Explain why MgO has a higher boiling point than SO2. 68. Explain the trend in boiling points down Groups 1, 2 and 7. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 17
69. Explain what is meant by the term orbital. What are the different types of orbital and how many of each are there? 70. Calculate the number of electrons in shell 4, showing your full working. 71. Draw an S and a P orbital. State their shape. 72. Draw an electron in box diagram and also write out the electron configuration for Ca and Ca 2+. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 18
73. Draw electron in box diagrams and below each write out the electron configuration for: (i) H (ii) Be (iii) O (iv) K + (v) Br (vi) Br - Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 19
74. Write out electron configurations only for the following atoms and ions: He N F Al 3+ P 3-75. Write out electron configurations for the following, proving that they do belong to the s or p block. Li s-block Na Ca B p-block P Cl 76. Prove that the cations Na + and Mg 2+ are isoelectronic by writing out their electronic configurations. 77. To which block in the Periodic Table do the following elements belong (i) Mg.. (ii) Si.. (iii) I.. (iv) Mn.. (v) Ag.. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 20
78. Balance the following equations. 1. Mg + N2 Mg3N2 2. Ba + HCl BaCl2 + H2 3. C + O2 CO2 4. C2H6 + O2 CO2 + H2O 5. Fe + Cl2 FeCl3 6. Mg + HNO3 Mg(NO3)2 + H2 7. CuCO3 + HCl CuCl2 + + CO2 + H2O 79. Construct balanced equations for reaction of the following elements with oxygen. Explain any properties of the oxides produced. (i) Na... (ii) Al... (iii) C... (iv) Si.. 80. Explain why Na2O has a higher melting point than CO2. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 21
81. Construct balanced equations for the reactions of Na and Al with: (i) oxygen (ii) water (iii) hydrochloric acid (iv) sulphuric acid. 82. The reaction between lithium metal and hydrochloric acid is a redox reaction. Write an equation for this reaction and prove that it is a redox reaction. 83. The element strontium forms a nitrate, Sr(NO3)2, which decomposes on heating as shown below. 2 Sr(NO3)2 (s) 2 SrO (s) + 4 NO2 (g) + O2 (g) Using oxidation numbers, explain why the reaction involves both oxidation and reduction. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 22
84. Assign oxidation numbers and say whether or not these are REDOX reactions. i) Mg + 2 HCl MgCl2 + H2 ii) 2 Ca + O2 2 CaO iii) SrO + H2O Sr(OH)2 iv) Mg + H2O MgO + H2 v) BaO + 2 HCl BaCl2 + H2O vi) Ca + 2 HCl CaCl2 + H2 85. Prove that the reaction below is a redox reaction. Fe2O3 + 3 CO 2 Fe + 3 CO2 Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 23
86. Complete the table below. What property of transition metals makes them useful as catalysts? Formula Name Oxidation no. of transition element CuCl2 Copper(I) chloride 87. Explain why Rb is more reactive than K but Ca is less reactive than K. 88. Magnesium and copper(ii) sulfate, CuSO4, take part in a displacement reaction. Write the equation for this reaction. Is the reaction a redox reaction? Why does the reverse reaction not take place? 89. Iron and copper(ii) sulfate, CuSO4, take part in a displacement reaction. Write the equation for this reaction. Is the reaction a redox reaction? Why does the reverse reaction not take place? Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 24
90. Write the equation for the reaction of bromide with chlorine, Cl2. Why does this reaction take place? 91. Calculate the molar mass of the following: 1. CuO 2. Cl2 3. HF 4. CaCO3 5. NH4NO3 6. Na2SO4 7. Al2(SO4)3 8. Zn(OH)2 92. Calculate the mass, in grams, for the following. 1. 2 mol of Na 2. 0.5 mol of Zn 3. 10 mol of Pb 4. 0.25 mol of SO2 5. 5 mol of Na2CO3 6. 0.2 mol of Br2 7. 0.01 mol of Ag2O 8. 0.02 mol of KMnO4 93. Calculate the amount, in mol, for the following. 1. 2.3 g of Na 2. 58.5 g of NaCl 3. 50.0 g of CaCO3 4. 40.0 g of CH4 5. 0.98 g of H2SO4 6. 8.0 g of Br2 7. 160.0 g of NaOH 8. 303.0 g of KNO3 94. Find the amount, in moles, of solute dissolved in water to form the following solutions. 1. 1 dm 3 of 0.2 mol dm -3 H2SO4 2. 100 cm 3 of 1 mol dm -3 KCl 3. 25 cm 3 of 2.5 mol dm -3 NaCl 4. 22.5 cm 3 of 0.2 mol dm -3 HCl 5. 2 dm 3 of 2 mol dm -3 H2SO4 6. 5 cm 3 of 5 mol dm -3 HNO3 Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 25
95. Find the concentration of the following solutions in mol dm -3. 1. 1 mol of HCl in 1 dm 3 2. 5 mol of HNO3 in 250 cm 3 3. 0.1 mol of HNO3 in 25 cm 3 4. 2.25 x 10-3 mol in 15 cm 3 5. 4 mol in 20 dm 3 6. 8.8 x 10-2 mol in 200 cm 3 96. 12.7 g of Cu reacts with excess O2 to produce CuO. 2 Cu + O2 2 CuO (i) Calculate the amount, in mol, of Cu used in the reaction. (ii) Calculate the amount, in mol, of CuO produced in the reaction. (iii) Calculate the mass, in grams, of CuO produced in the reaction. 97. 6.0 g of Mg reacts with an aqueous solution of CuSO4 to form MgSO4 and Cu. CuSO4 + Mg MgSO4 + Cu (i) Calculate the amount, in mol, of Mg used in the reaction. (ii) Calculate the amount, in mol, of Cu produced in the reaction. (iii) Calculate the mass, in grams, of Cu produced in the reaction. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 26
98. In a reaction, SrCO3 is used to neutralise 25 cm 3 of a 0.15 mol dm -3 HCl solution. SrCO3 + 2 HCl SrCl2 + H2O + CO2 (i) Calculate the amount, in mol, of HCl used in the reaction. (ii) Calculate the mass, in grams, of SrCO3 used to neutralise the HCl in the reaction. 99. In an experiment 0.50 g of K metal was added to 500 cm 3 of water making a solution of KOH. 2 K + 2 H2O 2 KOH + H2 (i) Calculate the amount, in mol, of K used in the reaction. (ii) Calculate the concentration, in mol dm -3, of the KOH solution formed. 100. An excess amount of Ba is treated with 200 cm 3 of 0.05 mol dm -3 HCl to form an aqueous solution of barium chloride. Ba + 2 HCl BaCl2 + H2 (i) Calculate the amount, in mol, of HCl used in the reaction. (ii) Calculate the concentration, in mol dm -3, of the BaCl2 solution formed. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 27
101. 1 Kg of MgO is used to neutralise a 0.04 mol dm -3 solution of HCl. MgO + 2 HCl MgCl2 + 2 H2O (i) Calculate the amount, in mol, of MgO used in the reaction. (ii) Calculate the volume, dm 3, of the HCl solution used. 102. 50 kg of pure sulfuric acid was accidently released into a lake when a storage vessel leaked. It was proposed that CaCO3 was used to neutralise it. Calculate the mass of CaCO3 required to neutralise the 50 kg of H2SO4. H2SO4 + CaCO3 CaSO4 + H2O + CO2 103. A student dissolved 2.794 g of an acid HY in 100 cm 3 of water. Once HY was fully dissolved, the student then added a further 150 cm 3 of water to make 250 cm 3 of a solution of HY in water. 25cm 3 of this HY solution was then titrated against a 0.0614 mol dm -3 of Na2CO3 solution, requiring 23.45 cm 3 of the Na2CO3 solution for complete neutralisation. 2 HY + Na2CO3 2 NaY + H2O + CO2 (i) Calculate the amount, in mol, of Na2CO3 used in the titration. (ii) Calculate the amount, in mol, of HY used in the titration. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 28
(iii) Calculate the amount, in mol, of HY in the original 250 cm 3 solution. (iv) Calculate the molar mass of HY. 104. A chemist reacts 1.00g of Cu with excess oxygen. After purification, 1.00g of CuO is isolated from the reaction. (i) Calculate the amount, in moles, of Cu reacted. 2 Cu + O2 2 CuO (ii) Determine the theoretical moles of CuO. (iii) Calculate the actual moles of CuO made. (iv) determine the percentage yield of the reaction. 105. A chemist reacts 1.00g of methanol, CH3OH, with an oxidant. After purification, 0.98g of methanol, CH2O, is isolated from the reaction. Determine the percentage yield. CH3OH + [O] CH2O + H2O Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 29
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