8.3. Group VII properties
A subsection of Chemistry, 0620, through 8. The Periodic Table
Listing 10 of 123 questions
The chemical elements are arranged in the Periodic Table in groups and periods. Describe how the metallic character of the elements changes from left to right across a period. The elements in Group I are known as the alkali metals. Describe two trends in the properties of the elements, going down Group I.  Chlorine, bromine and iodine are in Group VII of the Periodic Table. Aqueous chlorine reacts with aqueous sodium bromide to produce aqueous bromine and aqueous sodium chloride. Complete the symbol equation for this reaction. Cl 2 + NaBr → + 2NaCl Suggest why aqueous iodine does not react with aqueous sodium bromide. Complete the dot-and-cross diagram in Fig.3.1 for a molecule of iodine. Show outer shell electrons only. I I  Molten silver bromide is electrolysed using graphite electrodes. Name the product formed at each electrode. product at the anode product at the cathode  Fig.3.2 shows the apparatus used to electroplate a metal object with silver. power supply + – electrolyte containing Ag+ ions Label Fig.3.2 to show where the silver is deposited. State why objects are electroplated. 
0620_m24_qp_32
THEORY
2024
Paper 3, Variant 2
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The elements in Group VII of the Periodic Table are known as the halogens. Halogens can form halide ions. Identify the halogen with the lowest density at r.t.p. (room temperature and pressure). State the appearance of bromine at r.t.p. Use the Periodic Table to: ● give the symbol of the halogen with the highest atomic number ● deduce the number of occupied electron shells in an atom of this element.  Bromine molecules have covalent bonding. State what is meant by the term covalent bond. Name one halide ion which bromine molecules can displace. Explain why bromine can displace the halide ion in . Name a halide compound which can be used to detect the presence of water. Calcium chloride is an ionic compound. Complete the dot-and-cross diagram in for the ions in calcium chloride. Give the charges on each of the ions. Cl Cl Ca  Aqueous lead(ions are added to aqueous chloride ions. A white precipitate of insoluble lead(chloride, PbCl 2, is formed. Name a lead(compound which can be used in this reaction. Write the ionic equation for this reaction. Include state symbols. Name one other insoluble chloride. 
0620_m24_qp_42
THEORY
2024
Paper 4, Variant 2
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Use The halogens are a group of diatomic non-metals showing a trend in colour, state and reactivity. In this description, what is the meaning of diatomic, state? The table gives some information about some of the halogens. element melting point / oC boiling point / oC colour state at room temperature chlorine -101 -35 green bromine -7 +59 iodine +114 grey-black Complete the last column in the table to show the state of each of the halogens at room temperature. State the colour of bromine. Suggest a value for the boiling point of iodine. Complete the word equation for the reaction of chlorine with potassium iodide. chlorine + potassium iodide + Examiner's Use Draw a diagram to show the electronic structure of a chlorine molecule. Show only the outer electrons. State a use of chlorine. The structures of some substances containing halogens are shown below. Cl H Br Br Br F F F Cl – Na+ Na+ Cl – Na+ Cl – Na+ Cl – Na+ Cl – Cl – Na+ A B C D Which one of these structures, A, B, C or D, shows an element? Which one of these structures forms hydrochloric acid when dissolved in water? Complete the following sentence. Structure B conducts electricity when it is molten because Examiner's Use Astatine, At, is below iodine in Group VII of the Periodic Table. In which Period of the Periodic Table is astatine? How many protons does astatine have in its nucleus? Astatine has many isotopes. What do you understand by the term isotopes? The most common isotope of astatine has a nucleon number (mass number) of 210. Calculate the number of neutrons in this isotope of astatine.
0620_s05_qp_2
THEORY
2005
Paper 2, Variant 0
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For Examiner's Use Three of the halogens in Group VII are: chlorine bromine iodine How does their colour change down the Group? How does their physical state (solid, liquid or gas) change down the Group? Predict the colour and physical state of fluorine. colour physical state Describe how you could distinguish between aqueous potassium bromide and aqueous potassium iodide. test result with bromide result with iodide 0.015 moles of iodine react with 0.045 moles of chlorine to form 0.030 moles of a single product. Complete the equation. I2 + Cl2 Traces of chlorine can be separated from bromine vapour by diffusion. Which gas would diffuse the faster and why?
0620_s05_qp_3
THEORY
2005
Paper 3, Variant 0
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Use The halogens are a group of elements showing trends in colour, state and reaction with other halide ions. Complete the word equation for the reaction of chlorine with aqueous potassium bromide. chlorine + potassium bromide → + Explain why an aqueous solution of iodine does not react with potassium chloride. The table shows the properties of some halogens. halogen state at room temperature colour boiling point / °C density of solid / g cm-3 fluorine gas yellow 1.51 chlorine green −35 1.56 bromine liquid red-brown iodine solid 4.93 Complete the missing spaces in the table. Suggest values for the boiling point of fluorine, the density of bromine. How many electrons does an atom of fluorine have in total, in its outer shell? State a use for chlorine.
0620_s07_qp_2
THEORY
2007
Paper 2, Variant 0
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For Examiner's Use Use your copy of the periodic table to help you answer these questions. Predict the formula of each of the following compounds. barium oxide boron oxide Give the formula of the following ions. sulphide gallium Draw a diagram showing the arrangement of the valency electrons in one molecule of the covalent compound nitrogen trichloride. Use x to represent an electron from a nitrogen atom. Use o to represent an electron from a chlorine atom. Potassium and vanadium are elements in Period IV. State two differences in their physical properties. Give two differences in their chemical properties. For Examiner's Use Fluorine and astatine are halogens. Use your knowledge of the other halogens to predict the following: The physical state of fluorine at r.t.p. The physical state of astatine at r.t.p. Two similarities in their chemical properties [Total 15]
0620_s07_qp_3
THEORY
2007
Paper 3, Variant 0
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For Examiner's Use Bromine is an element in Group VII of the Periodic Table. Write the formula for a molecule of bromine. Complete the diagram below to show the arrangement of the molecules in liquid bromine. represents a bromine molecule A teacher placed a small amount of liquid bromine in the bottom of a sealed gas jar of air. After two minutes brown fumes were seen just above the liquid surface. After one hour the brown colour had spread completely throughout the gas jar. start after 2 minutes after liquid bromine air Use the kinetic particle theory to explain these observations. For Examiner's Use Magnesium salts are colourless but Group VII elements are coloured. An aqueous solution of magnesium bromide reacts with an aqueous solution of chlorine. magnesium bromide + chlorine magnesium chloride + bromine State the colour change in this reaction. A solution of magnesium bromide will not react with iodine. Explain why there is no reaction. The structures of some compounds containing bromine are shown below. Na+ Br – Na+ Br – Na+ Br – Na+ Br – Na+ Br – Na+ Br – Na+ Br – Na+ Br – Zn2+ Br – Br – Zn2+ Br – Br – Zn2+ Br – Br – Zn2+ Br – Br – A B C D H Br Br F F F Write the simplest formula for the substance with structure A. State the name of the substance with structure D. State the type of bonding within a molecule of structure C. Which two structures are giant structures? and Why does structure A conduct electricity when it is molten?
0620_s09_qp_2
THEORY
2009
Paper 2, Variant 0
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Questions Discovered
123