Name: _______________________________________________ Unit 1 Chemistry past paper questions Date: Time: Total marks available: Total marks achieved: ______ Questions Q1. Lithium, Li, is a metal in group 1 of the periodic table. (i) What is the name given to group 1 of the periodic table? (1) A alkali metals B alkaline earth metals C halogens D transition metals (ii) Lithium has an atomic number of 3. Complete the electronic configuration of lithium. (1) 1s........ 2s........ (iii) Write the equation to show the first ionisation energy of lithium. (2) ............................................................................................................................................. (Total for question = 4 marks) Q2. Oxygen exists as the molecule O2 in the Earth's atmosphere and is needed for combustion. A student burns magnesium in air to produce 1.40 g of magnesium oxide. The theoretical yield of magnesium oxide for the experiment is 2.00 g. (i) Calculate the percentage yield for the student's experiment. (2) percentage yield = ........................................................... % (ii) Magnesium reacts with oxygen to form magnesium oxide. 2Mg + O2 → 2MgO 2.43 g of magnesium was burned. Calculate the theoretical yield of magnesium oxide. (3) theoretical yield of magnesium oxide = ........................................................... g (Total for question = 5 marks) Q3. Ammonium chloride, ammonium sulfate and ammonium nitrate are used in fertilisers. Ammonia reacts with nitric acid to make ammonium nitrate. NH3 + HNO3 → NH4NO3 Calculate the mass of ammonia required to make 5.0 g of ammonium nitrate. relative formula mass of NH3 = 17 relative formula mass of NH4NO3 = 80 (3) mass of ammonia ........................................................... g (Total for question = 3 marks) Q4. Calcium is a metal. Word equations for two reactions of calcium are shown. The equation for the reaction of dilute hydrochloric acid with calcium is Ca + 2HCl → CaCl2 + H2 Calculate the maximum mass of calcium chloride produced by reacting 8.02 grams of calcium with excess hydrochloric acid. relative atomic mass: Ca = 40.1 relative formula mass: CaCl2 = 111.1 Show your working. (3) Maximum mass = ........................................................... g (Total for question = 3 marks) Q5. Magnesium chloride, MgCl2, is an important industrial chemical. It can be made by reacting magnesium with dilute hydrochloric acid. Calculate the number of moles of hydrochloric acid in 50 cm 3 of 0.2 M hydrochloric acid. Show your working. ........................................................... moles (Total for question = 3 marks) Q6. Magnesium sulfate is an ionic compound. (i) A learner is given 6.02 g of magnesium sulfate. Calculate the number of moles of magnesium sulfate. (relative formula mass of MgSO4 = 120.4) (1) number of moles = ........................................................... (ii) The learner dissolves the magnesium sulfate in distilled water to make 500 cm 3 of solution. Calculate, using your answer to (c)(i), the molar concentration of this magnesium sulfate solution. If you did not get an answer for (c)(i), use the value 0.04 for the number of moles. Show your working. (3) molar concentration = ........................................................... mol dm -3 (Total for question = 4 marks) Q7. Figure 1 shows a molecule of the covalent compound tetrachloromethane. A sample of chlorine contains 80% chlorine-35 and 20% chlorine-37. Calculate the relative atomic mass of this sample of chlorine. Show your working. (2) relative atomic mass = ........................................................... (Total for question = 2 marks) Q8. Manganese, Mn, is a metal. It has a metallic structure. KMnO4 is a useful compound of manganese. Calculate the relative formula mass for KMnO4. (2) relative formula mass = ........................................................... (Total for question = 2 marks) Q9. Ammonium chloride, ammonium sulfate and ammonium nitrate are used in fertilisers. Calculate the relative formula mass of ammonium chloride, NH4Cl. (2) relative formula mass = ........................................................... (Total for question = 2 marks) Q10. Iron is extracted from iron oxide in a blast furnace. The balanced equation for the reaction is Fe2O3 + 3CO → 2Fe + 3CO2 Calculate the relative formula mass of iron oxide. Show your working. Relative formula mass = ........................................................... (Total for question = 2 marks) Q11. The table shows some data about three compounds. Calculate the relative molecular mass for ethanol. Show your working. Relative molecular mass = ........................................................... (Total for question = 2 marks) Q12. Magnesium chloride, MgCl2, is an important industrial chemical. It can be made by reacting magnesium with dilute hydrochloric acid. Calculate the relative molecular mass for magnesium chloride. Show your working. ........................................................... (Total for question = 2 marks) Q13. Which equation shows the first ionisation of potassium? (1) A B C D – – K(g) → K (g) + e K–(g) → K+ (g) + e– K+(g) → K– (g) + e– K(g) → K+ (g) + e– (Total for question = 1 mark) Q14. Figure 1 shows a molecule of the covalent compound tetrachloromethane. Complete the dot and cross diagram, in Figure 2, for tetrachloromethane, CCl 4. Show outer electrons only. (2) (Total for question = 2 marks) Q15. Ammonium chloride, ammonium sulfate and ammonium nitrate are used in fertilisers. Ammonia reacts with sulfuric acid to form ammonium sulfate. Complete and balance the equation for this reaction. (2) ..................NH3 + ................................... → (NH4)2SO4 (Total for question = 2 marks) Q16. Ammonium chloride, ammonium sulfate and ammonium nitrate are used in fertilisers. Figure 1 shows the arrangement of electrons in the outer shell of an atom of nitrogen and in an atom of hydrogen. Complete the dot and cross diagram to show the bonding in the ammonium ion, . (2) (Total for question = 2 marks) Q17. A phosphorus atom contains 15 electrons. Complete the electronic configuration for a phosphorus atom. (2) (Total for question = 2 marks) Q18. Chemists use the periodic table to predict the chemical properties of elements based on their location in the table. Part of the periodic table is shown. The letters, A, B, C and D, represent four different elements. Complete the electronic configuration for an atom of sodium. 1s2 2s2 ............................................................................................................ (Total for question = 1 mark) Q19. Magnesium sulfate is an ionic compound. Magnesium reacts with sulfuric acid to form magnesium sulfate and hydrogen. Complete the equation for this reaction. (2) (Total for question = 2 marks) Q20. (i) Figure 2 shows the relative melting points of some of the elements in period 2. Figure 2 Complete Figure 2 to show how the relative melting points change from Be to N. (2) (ii) Table 1 shows the atomic numbers and melting points of the elements in group 7. Table 1 Explain why the melting point increases as the atomic number increases. (3) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (Total for question = 5 marks) Q21. An oxygen atom contains 8 electrons. Complete Figure 1 to show the arrangement of electrons in an oxygen atom. (2) Figure 1 (Total for question = 2 marks) Q22. Calcium is a metal. Word equations for two reactions of calcium are shown. Complete the word equation for the reaction of calcium with sulfuric acid. (2) calcium + sulfuric acid → ...................................................................................................................... (Total for question = 2 marks) Q23. Table salt contains sodium chloride. Sodium chloride can be prepared by reacting chlorine with sodium. (i) Describe how a chlorine atom forms a chloride ion, Cl −. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (ii) Sodium reacts with chlorine to form sodium chloride. The balanced equation for the reaction is 2Na + Cl2 → 2NaCl In an experiment, 4.6 g of sodium was reacted with chlorine. The actual yield of the experiment was 7.5 g. Calculate the percentage yield. (relative formula mass of sodium chloride = 58.5) Show your working. (4) Percentage yield = ........................................................... % (Total for question = 6 marks) Q24. Aluminium is used to make drinks cans. Describe the structure and bonding in aluminium metal. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (Total for question = 4 marks) Q25. Magnesium sulfate is an ionic compound. Describe the structure of an ionic compound. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (Total for question = 2 marks) Q26. A student collected some data about the atomic radius and ionic radius of three elements and their ions. Table 2 shows the data. Table 2 Discuss the atomic radius and ionic radius data in Table 2. (Total for question = 6 marks) Q27. Manganese, Mn, is a metal. It has a metallic structure. Manganese and zinc are both metals in the d block of the periodic table. Table 1 shows some information about manganese and zinc. Table 1 Discuss why manganese is classified as a transition metal, but zinc is not. (Total for question = 6 marks) Q28. Potassium iodide, KI, is an ionic compound. (i) Draw a dot and cross diagram to show the bonding in potassium iodide. Show the outer electrons only. (3) (ii) Potassium iodide is soluble in water. A student dissolves 16.6 g of potassium iodide in distilled water and makes the volume of the solution up to 500 cm3. Calculate the molar concentration of the solution produced. (relative formula mass of potassium iodide = 166) Show your working. (4) Concentration = ........................................................... mol dm −3 (Total for question = 7 marks) Q29. Table salt contains sodium chloride. Sodium chloride can be prepared by reacting chlorine with sodium. A chlorine molecule, Cl2, contains two covalently bonded chlorine atoms. Draw a dot and cross diagram to show the bonding in a molecule of chlorine. Show the outer electrons only. (Total for question = 2 marks) Q30. Magnesium chloride, MgCl2, is an important industrial chemical. It can be made by reacting magnesium with dilute hydrochloric acid. Draw dot-and-cross diagrams to show the arrangement of the outer electrons in the magnesium ion and the two chloride ions in magnesium chloride, MgCl 2. (Total for question = 3 marks) Q31. Oxygen exists as the molecule O2 in the Earth's atmosphere and is needed for combustion. Draw the dot and cross diagram for a molecule of oxygen, O 2 . (2) Show the outer electrons only. (Total for question = 2 marks) Q32. Fluorine, chlorine, bromine and iodine are the first four elements in group 7 (the halogens). The halogens all have similar chemical properties because of their electronic configuration. (i) Identify the correct electronic configuration for an atom of fluorine. (1) A B C D (ii) Fluorine atoms can react to become fluoride ions. Electron affinity is one way of measuring how easily a fluorine atom becomes a fluoride ion. Identify the correct word in each sentence to complete Paragraph 1. Underline the words you have chosen. (2) (iii) The electronegativity of the halogens changes down group 7. Explain how electronegativity changes down group 7. (3) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (Total for question = 6 marks) Q33. Industrial chemists have to understand the chemistry of oxides. For example, silicon dioxide is used in glass making and carbon monoxide is used in the extraction of iron from iron ore. Period 3 elements bond with oxygen to form oxides. The type of bonding in these oxides depends on the electronegativity of each element in the oxide. The table shows the electronegativity of some period 3 elements, as well as for oxygen. Explain how bonding in the oxides of elements in period 3 changes across the period. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (Total for question = 6 marks) Q34. Industrial chemists have to understand the chemistry of oxides. For example, silicon dioxide is used in glass making and carbon monoxide is used in the extraction of iron from iron ore. (i) Explain how burning carbon in air can lead to the formation of carbon monoxide. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (ii) Write the balanced equation for the reaction between silicon and oxygen. (2) ............................................................................................................................................. (Total for question = 4 marks) Q35. Connectors in some electrical circuits are coated in gold. One property of gold is its ability to conduct electricity. Explain how gold conducts electricity. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. (Total for question = 3 marks) Q36. Water, H2O, and methane, CH4, are simple covalent compounds. The boiling point of water is 100°C. The boiling point of methane is –164°C. Explain the difference in boiling points between water and methane, in terms of intermolecular forces present. (Total for question = 6 marks) Mark Scheme Q1. Q2. Q3. Q4. Q5. Q6. Q7. Q8. Q9. Q10. Q11. Q12. Q13. Q14. Q15. Q16. Q17. Q18. Q19. Q20. Q21. Q22. Q23. Q24. Q25. Q26. Q27. Q28. Q29. Q30. Q31. Q32. Q33. Q34. Q35. Q36.
