C4 Revision Questions Bumper Pack

Transcription

1 C4 Revision Questions Bumper Pack You will need a Periodic Table to answer these questions!! C4a Atomic structure 1. Write down a definition of an element. 2. Write down: a) the approximate radius of an atom? b) the approximate mass of an atom? 3. In calcium carbonate (CaCO 3 ) a) State how many different elements are present. b) State how many different atoms are present. 4. What is the relative charge on: a) a proton b) a neutron c) an electron 5. What is the relative mass of: a) A proton b) a neutron c) an electron 6. Explain why atoms have no overall charge on them. 7. What subatomic particles are found in the nucleus? 8. What does the atomic number of an element tell you?

2 9. What are isotopes? 10. Write down the atomic number of the following elements: a) sodium b) sulfur c) fluorine 11. What determines the order of the elements in the Periodic Table? 12. Write down the mass number of the following elements: a) helium b) calcium c) aluminium 13. Write down how many protons, neutrons and electrons are in the following atoms: a) potassium b) hydrogen c) nitrogen 14. Two atoms both have an atomic number of 17, but one has a mass number of 35 and one has a mass number of 37. What word can be used to describe these atoms? 15. Write down the electronic structure of the following atoms: (e.g. 2,8,8, ) a) Argon b) Oxygen c) Magnesium 16. How did the following scientists contribute to the development of the theory of atomic structure? a) Dalton b) J. J. Thomson c) Rutherford d) Bohr

3 C4b Ionic bonding 1. What is an ion? 2. How do positive ions form? 3. How do negative ions form? 4. Do metals form positive or negative ions? 5. Why do atoms gain or lose electrons? 6. Select from the following 6 symbols: H + H 2 O Na + Mg Cl 2 Br - a) A symbol for an ion b) A symbol for an atom c) A symbol for a molecule d) A symbol for a negative ion 7. What holds the ions together in an ionic compound? 8. How are the ions arranged in an ionic compound? 9. Why do ionic compounds have high melting-points? 10. Why does sodium chloride have a lower melting point than magnesium oxide? 11. Why can t ionic compounds conduct electricity when solid?

4 12. What two things can be done to an ionic compound to make it conduct electricity? 13. Sodium oxide is made from Na + ions and O 2- ions. What is its formula? 14. Calcium bromide is made from Ca 2+ ions and Br - ions. What is its formula? 15. Aluminium chloride is made from Al 3+ ions and Cl - ions. What is its formula? 16. Sodium has an electronic structure 2,8,1. Chlorine has the electronic structure 2,8,7. They react together to form an ionic compound, NaCl. Draw dot-cross diagrams to show the ions in sodium chloride. Include the charges on the ions. 17. Draw a dot-cross diagram of magnesium oxide. The electronic structure of magnesium is 2,8,2 and for oxygen is 2,6. Include in your answer the ions formed and the charges on these ions.

5 C4c The periodic table and covalent bonding 1. What is a molecule? 2. How many atoms are in a molecule of H 2 SO 4? 3. How many types of atoms are in a molecule of HNO 3? 4. What types of atoms take part in covalent bonding? 5. How does covalent bonding occur? 6. Do covalent compounds generally have high or low melting points? Explain why. 7. Why doesn t water conduct electricity? 8. Name two elements in group Name 2 elements in period Name the element in group 2 and period 3.

6 11. What do all the elements in a group have in common? (Hint: Think about their electronic structure) 12. What do all the elements in a period have in common? (Hint: Think about their electronic structure) 13. What group and period is phosphorus in? 14. Draw dot-cross diagrams to show the covalent bonding in the following compounds: a) Hydrogen (H 2 ) b) Water (H 2 O) c) Methane (CH 4 ) d) Carbon dioxide (CO 2 ) 15. How did Newlands and Mendeleev help classify the elements?

7 C4d Group 1 elements 1. What are the group 1 elements commonly known as? 2. Explain why the group 1 metals are stored in oil. 3. What will you see when potassium reacts with water? 4. Write a word equation for this reaction. 5. Write a balanced symbol equation for this reaction. 6. How would expect caesium to react with water? 7. Why do all of the group 1 metals have similar properties? 8. How does the reactivity of the group 1 metals vary as you go down the group? 9. Explain why this trend in reactivity occurs. 10. When lithium atoms react with water they lose an electron to form lithium ions. Write an ionic equation to show this.

8 11. Explain why this reaction involves oxidation of the lithium atoms. 12. State the three stages required when performing flame tests. 13. What colour flame is seen when sodium compounds undergo a flame test? 14. What colour flame is seen when lithium compounds undergo a flame test?

9 C4e Group 7 elements 1. State the name the group 7 elements are commonly known as. 2. Give the colours and physical state of the following group 7 elements: a) Chlorine b) Bromine c) Iodine 3. State one use of each of the following group 7 elements: a) Chlorine b) Iodine 4. Potassium and fluorine readily react together to form a white crystalline solid. Write a word equation and a balanced symbol equation for this reaction. 5. Use ideas about electronic structure to explain why the group 7 elements have similar properties. 6. How does the reactivity of the group 7 elements vary as you go down the group? Use ideas about electronic structure to explain why this occurs.

10 7. Chlorine gas is bubbled through a solution of potassium bromide. a) What colour change is seen? b) Why does a reaction occur? c) What is the name for this type of reaction? d) Write a word and balanced symbol equation for this reaction. e) In this reaction atoms in a chlorine molecule react to form chloride ions by gaining electrons. Write an ionic equation to show this. 8. Why can this process be described as reduction? 9. Given the following boiling points, predict the boiling point of fluorine and astatine: Fluorine Chlorine Bromine Iodine Astatine -35 o C +59 o C +170 o C

11 C4f Transition metals 1. From the Periodic Table give the name and symbol of 5 transition elements. 2. Name four typical properties of metals that transition metals have. 3. Name one way in which transition metals are different to other metals. 4. What colour are copper compounds typically? 5. What colour are iron (II) compounds typically? 6. What colour are iron (III) compounds typically? 7. What colour are sodium compounds typically? 8. Why are transition metals often used in industrial processes (what is their role)? 9. Describe the industrial process that uses iron. 10. Describe the industrial process that uses nickel.

12 11. What is a catalyst? 12. What is a thermal decomposition reaction. 13. What is often observed when a transition metal undergoes a thermal decomposition reaction? 14. Write a word equation for the decomposition of copper carbonate. 15. Write a balanced symbol equation for the decomposition of copper carbonate (CuCO 3 ). 16. How can the gas given off during in this reaction be identified (what is used and what is observed)? 17. Explain what is meant by a precipitate. 18. Describe what is seen when sodium hydroxide solution is added to solutions of the following ions: a) Cu 2+ b) Fe 2+ c) Fe When hydroxide ions are added to a solution containing Cu 2+ ions, they react to form copper hydroxide. Write a balanced symbol equation for this reaction.

13 C4g Metal structure and properties. 1. Name the property that makes metals good for making jewellery. 2. Name the property that makes metals good for making saucepans. 3. Name the property that makes metals good for making light bulb filaments. 4. Metals are good conductors of electricity. Name one use of this property. 5. Metals are strong. Name one use of this property. 6. Metals are hard. Name one use of this property. 7. Which metal is most often used for electrical wiring due to its low electrical resistance? 8. Why is steel more often used for large building projects rather than iron? 9. Draw a labelled diagram to explain the arrangement of particles in a metal.

14 10. What holds the atoms together in a metal? 11. Why do metals have high melting points? 12. Why can metals conduct electricity? 13. When a metal conducts electricity, what does the current consist of? 14. What type(s) of energy is the electrical energy converted to by resistance in a wire? 15. What is a superconductor? 16. Name 3 potential benefits of superconductors. 17. Explain the main problem with using superconductors.

15 C4h Purifying and testing water 1. Explain why it is important to conserve water. 2. Explain why drinking water may contain the pollutants listed below: a) Nitrates b) Lead compounds c) Pesticides 3. The water purification process is made up of three main processes: filtration, sedimentation and chlorination. Describe what happens during each of these three processes. - Filtration - Sedimentation - Chlorination 4. Why are some soluble substances not removed from water during purification? 5. One method of making fresh water is to distill seawater. State one disadvantage of this method. 6. What type of aqueous ions can silver nitrate be used to test for?

16 7. What type of aqueous ions can barium chloride be used to test for? 8. Write out a word and balanced symbol equation for the reaction between silver nitrate (AgNO 3 ) and potassium chloride (KCl). 9. What type of reaction is this? 10. What would be observed when silver nitrate reacts with the following ions: a. Chloride b) Bromide c) Iodide 11. Write out a word and balanced symbol equation for the reaction between barium chloride (BaCl 2 ) and magnesium sulfate (MgSO 4 ). 12. What would be observed during this reaction? 13. Substance A forms a cream precipitate when mixed with silver nitrate solution but doesn t form a precipitate when mixed with barium chloride solution. What ions are present in substance A? 14. Substance B forms a white precipitate when mixed with barium chloride solution but doesn t form a precipitate when mixed with silver nitrate solution. What ions are present in substance B?

17 The Answers C4a 1. An element is made of only one type of atom and can t be broken down chemically. 2. a) m b) g 3. a) 3 b) 5 4. a) +1 b) 0 c) a) 1 b) 1 c) 1/2000 or 0 6. The charge of the protons and the charge of the electrons cancel each other out. 7. Protons and neutrons. 8. The number of protons in an atom. 9. Atoms with the same atomic number but different mass numbers or atoms with the same number of protons but different numbers of neutrons. 10. a) 11 b) 16 c) Elements are arranged in order of increasing atomic number. 12. a) 4 b) 40 c) a) 19p, 20n, 19e b) 1p, 0n, 1e c) 7p, 7n, 7e 14. Isotopes 15. a) 2,8,8 b) 2,6 c) 2,8,2 16. a) Dalton he said that everything was made up of atoms & that all atoms of a particular element are identical. Different elements are made from different types of atom. b) J. J. Thomson discovered that atoms contained smaller, negativelycharged particles called electrons. c) Rutherford discovered that an atom is mostly empty space with electrons arranged around a central nucleus. d) Bohr discovered that electrons move in orbits (shells) around the nucleus. C4b 1. Formed when an atom gains or loses electrons. 2. Atoms lose electrons. 3. Atoms gain electrons. 4. Positive ions. 5. In order to achieve a full outer shell of electrons. 6. a) H + or Na + or Br - b) Mg c) H 2 O or Cl 2 d) Br - 7. Electrostatic forces between positive and negative ions. 8. In a highly regular pattern or in a giant ionic lattice. 9. The positive and negative ions are held together by strong electrostatic forces. 10. MgO is made up of Mg 2+ and O 2- ions which have double the charge of the Na + and Cl - ions in NaCl. This means the attraction between the ions is stronger in

18 MgO. Also, the ions in MgO aree smaller so can pack together more closely. This also makes the attraction n between them stronger. 11. The ions can t move. 12. Melt it or dissolve it in water. 13. Na 2 O 14. CaBr AlCl C4c 1. A molecule is formed from non-metal atoms bonded together Non-metals 5. Non-metal atoms share electrons. 6. Low weak intermolecular forces. 7. There are no free electrons orr ions thatt can conduct electricity. 8. Oxygen, sulfur, selenium, tellurium or polonium. 9. Lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorinee or neon. 10. Magnesium 11. The same number of electronss in their outer shell. 12. The same number of occupied electron shells. 13. Group 5, period a) b) c) d) 15. Newlands law of octaves. Hee noticed that everyy eight element had similar properties so arranged them inn rows of seven. Mendeleev he arranged elements in a table in order of increasing relative atomic mass. He swapped somee elements around iff it workedd better and left gaps for elements for elements that hadn t yet been discovered.

19 C4d 1. The alkali metals. 2. Otherwise they will react with the oxygen in the air. 3. Potassium moves rapidly over the surface of the water and catches fire with a lilac flame. 4. Potassium + water potassium hydroxide + hydrogen 5. 2K + 2H 2 O 2KOH + H 2 6. Very violently/explosively. 7. They all have 1 electron in their outer shell/they all lose 1 electron when they react. 8. It increases. 9. It becomes easier to lose an electron as the atoms get bigger. This is because the outer shell electrons are further from the nucleus. 10. Li Li + + e Oxidation is loss of electrons. 12. Moisten the wire with hydrochloric acid, dip the wire into the compound, put the wire into a blue Bunsen flame. 13. Yellow 14. Red C4e 1. The halogens. 2. a) yellow-green gas b) orange-brown liquid c) dark grey (not black) solid 3. a) Kill micro-organisms in drinking water/pesticides/making PVC b) Antiseptic 4. Potassium + fluorine potassium fluoride 2K + F 2 2KF 5. They all have 7 electrons in their outer shell/they all gain 1 electron when they react. 6. It decreases. It becomes harder to gain an electron as the atoms get bigger. This is because the outer shell is further from the nucleus. 7. a) An orange-brown solution forms. b) Chlorine is more reactive than bromine so can displace it from one of its salts. c) Displacement reaction. d) Chlorine + potassium bromide potassium chloride + bromine Cl 2 + 2KBr 2KCl + Br 2 e) Cl 2 + 2e - 2Cl - 8. Reduction is a gain of electrons. 9. Fluorine: any sensible answer less than -80 o C Astatine: any sensible answer more than +230 o C

20 C4f 1. Any 5 transition metals and matching symbols. E.g. Iron Fe, Cobalt Co. 2. Any four from: good conductors of heat and electricity, lustrous, ductile, hard, strong, malleable, ductile, sonorous, high melting points. 3. They are coloured. 4. Blue or green 5. Light green 6. Orange or brown 7. White 8. Catalysts 9. The Haber process forms ammonia which is needed to make fertilisers. 10. Formation of margarine (hydrogenation of unsaturated fats). 11. A substance that speeds up the rate of a chemical reaction while remaining unchanged. 12. A reaction in which substances break down when heated. 13. A colour change. 14. Copper carbonate copper oxide + carbon dioxide 15. CuCO 3 CuO + CO Limewater it turns cloudy/milky. 17. A insoluble solid that forms when two solutions are mixed. 18. a) A pale blue precipitate. b) A dirty green precipitate. c) An orange-brown precipitate. 19. Cu OH - Cu(OH) 2 C4g 1. Lustrous 2. Good conductor of heat 3. High melting point 4. Electrical wiring. 5. Bridges 6. Anvils/hammers 7. Copper 8. It is stronger and more flexible. 9. Must show a regular arrangement of positive ions (labelled) and a random arrangement of delocalised electrons (labelled). 10. Metallic bonding which is a strong electrostatic attraction between positive ions and a negatively charged sea of delocalised electrons. 11. The strong forces of attraction between positive ions and delocalised electrons have to overcome. 12. The delocalised electrons can move easily. 13. Electrons flowing through a metal. 14. Heat energy. 15. A material that conducts electricity with little or no resistance.

21 16. No energy would be lost in wires as heat. Electronic circuits in computers could be faster. Stronger electromagnets could be made. 17. Superconductors only lose their resistance at extremely low temperatures. C4h 1. Fresh water is a limited resource but we need a lot of it for drinking and industrial and domestic uses. The demand for fresh water increases each year. 2. a) from fertiliser that runs off fields b) from old lead pipes c) from spraying crops in fields close to water resources 3. Filtration removes solid particles by passing the water through gravel and sand beds. Sedimentation iron sulfate or aluminium sulfate are added to the water which makes fine particles clump together and settle at the bottom. Chlorination kills microbes in the water, helping to prevent disease. 4. Soluble substances can t be filtered out so therefore can t be removed from the water. 5. A large amount of energy is needed making it a very expensive process. 6. Halide ions 7. Sulfate ions 8. Silver nitrate + potassium chloride silver chloride + potassium nitrate AgNO 3 + KCl AgCl + KNO 3 9. Precipitation reaction 10. a) White precipitate b) Cream precipitate c) Yellow precipitate 11. Barium chloride + magnesium sulfate barium sulfate + magnesium chloride BaCl 2 + MgSO 4 BaSO 4 + MgCl White precipitate 13. Bromide ions 14. Sulfate ions