9701_s22_qp_23 - revisedeck

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Define first ionisation energy. Successive ionisation energies for elementA are shown in Table1.1. Table 1.1 ionisation 1st 2nd 3rd 4th 5th 6th 7th 8th ionisation energy / kJ mol–1 11 000 13 300 71 000 84 100 Use Table1.1 to deduce the group of the Periodic Table that A belongs to. Explain your answer. Group Across Period3 there is a general trend for first ionisation energies to increase due to the increase in attraction between the nucleus and the outer electron. Explain why the first ionisation energy of sulfur is less than the first ionisation energy of phosphorus. In an Al 2+ ion the nuclear attraction for the outer electron is stronger than in an atom of Na. Compare the electronic structures of Al 2+ and an atom of Na and explain why the third ionisation energy of aluminium is greater than the first ionisation energy of sodium. An isotope of copper has a relative isotopic mass of 65. Complete Table1.2 for an atom of copper-65. Table 1.2 atomic number nucleon number number of neutrons electronic arrangement copper-65 The element copper has a relative atomic mass of 63.5. Calculate how many atoms are present in 1.05 g of copper. atoms of copper present = Copper has a melting point of 1085 °C and a high electrical conductivity. Explain these properties of copper by referring to its structure and bonding.

1. Atomic structure → 1.4. Ionisation energy

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Period3 elements and their compounds show trends in their physical properties. On Fig.2.1 sketch a graph to show the melting points of the first five elements in Period3. melting point Na Mg Al Si P Complete Table2.1 with information for sodium chloride and phosphorus(chloride. Table 2.1 sodium chloride phosphorus(chloride state at room temperature name of change which occurs on addition of water pH of final solution Tennessine, Ts, is an unstable man-made element. It is found below astatine, At, in Group 17. The chemical properties of Ts and its compounds have only been predicted. Suggest an equation for the reaction of NaTs and Br2. Assume that Ts follows the same trends as the other elements in Group17. Explain your answer. equation explanation Some scientists predict that Ts has properties typical of metals like copper. Complete Table 2.2 with: ● the predicted melting point of tennessine ● the lattice structure of solid chlorine, bromine and tennessine. Assume that Ts has properties typical of metals like copper. Table 2.2 element chlorine bromine tennessine melting point / °C –101 –7.2 lattice structure of crystalline solid

9. The Periodic Table: chemical periodicity → 9.2. Periodicity of chemical properties of the elements in Period 3

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G belongs to a group of compounds called ethers. H H C H H C H H C H H C H H O G When G, C4H10O, is heated, thermal decomposition occurs. C4H10O→ C2H6+ CO+ CH4∆H = –7.00 kJ mol–1 The atoms in a molecule of CO are held together by a triple covalent bond. One of these bonds is a coordinate (dative covalent) bond. Draw a dot-and-cross diagram to show the arrangement of outer electrons in a CO molecule. Use ● to represent electrons from an oxygen atom. Use × to represent electrons from a carbon atom. Calculate the bond energy of C≡O using the bond energy values in Table3.1 and the enthalpy change, ∆H, for the thermal decomposition of G. Show your working. Table 3.1 bond bond energy / kJ mol–1 C–C C–O (in G) C–H bond energy (C≡O) = kJ mol–1 When G, C4H10O, is heated in a sealed container, an equilibrium mixture is produced. C4H10OC2H6+ CO+ CH4Complete the expression for the equilibrium constant, Kc, for this reaction. State the units of Kc. Kc = units = Thermal decomposition of G in the presence of I2 affects the activation energy, Ea, for the reaction. Table3.2 shows Ea for the thermal decomposition of G with and without I2. Table 3.2 reaction Ea (with I2) / kJ mol–1 Ea / kJ mol–1 C4H10O→ C2H6+ CO+ CH4143 State what effect adding I2 to the reaction mixture has on the value of Kc. Explain your answer. Fig. 3.2 shows the Boltzmann distribution of energies for molecules of G at constant temperature, T °C. Sketch, on Fig.3.2, the Boltzmann distribution of energies for molecules of G at a higher temperature, (T+100) °C. number of molecules energy Ea The functional group in G is an oxygen atom bonded to two carbon atoms. H H C H H C H H C H H C H H O G G, H and J are structural isomers with molecular formula C4H10O. H and J are straight chain molecules. Table3.3 shows the boiling points and reactions of G, H and J when heated under reflux with excess acidified K2Cr2O7. Table 3.3 G H J boiling point / °C heat under reflux with excess acidified K2Cr2O7 remains orange orange to green orange to green Identify the type of structural isomerism shown between G and H using the information in Table3.3. Identify the type of structural isomerism shown between H and J using the information in Table3.3. Draw a possible structure for H and for J. State the systematic name for each structure. H name J name K has molecular formula C3H6O. When K is added to 2,4-dinitrophenylhydrazine, an orange precipitate forms. When K is warmed with Tollens’ reagent, a silver mirror forms. Draw the displayed formula of K. K

3. Chemical bonding → 3.4. Covalent bonding and coordinate (dative covalent) bonding

5. Chemical energetics → 5.1. Enthalpy change, \(\Delta H\)

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2-methylpropene reacts with HCl at room temperature. The major organic product is 2-chloro-2-methylpropane. Complete Fig. 4.1 to show the structure of the intermediate and mechanism for this reaction. Include charges, dipoles, lone pairs of electrons and curly arrows as appropriate. C C H H H Cl Cl C H3C H3C CH3 CH3 H3C Explain why, in this reaction, 2-chloro-2-methylpropane is produced at a higher yield than 1-chloro-2-methylpropane. Two bottles labelled Q and M each contain a straight-chain halogenoalkane with molecular formula C4H9X, where X represents Cl, Br or I. A sample from each bottle is added to separate samples of equal amounts of aqueous silvernitrate in ethanol. In each reaction, the same organic product, T, and a precipitate are made, as shown in Fig.4.2. Q T M AgNO3in ethanol AgNO3in ethanol Table4.1 describes the colour of each of the precipitates made. Table 4.1 halogenoalkane added to AgNO3in ethanol colour of precipitate Q white M yellow Identify the functional group present in T and name the type of reaction that occurs using the information in Fig.4.2 and Table4.1. functional group in T type of reaction Construct an ionic equation to describe the formation of the yellow precipitate produced when M reacts with AgNO3in ethanol. Describe which reagent, Q or M, will produce a precipitate more quickly when each is added to AgNO3in ethanol. Explain your answer. reagent When pure T is added to alkaline I2, a yellow precipitate and an anion, L, are made. Identify the anion L. Deduce the structure of the straight-chain halogenoalkane M.

15. Halogen compounds → 15.1. Halogenoalkanes

11. Group 17 → 11.3. Some reactions of the halide ions

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But-2-ene reacts with KMnO4 to form organic product, Y. Y does not react with Na2CO3. A gas is produced when an excess of Na is added to Y. Describe the conditions for the KMnO4 used in the reaction to form Y from but-2-ene. 24.0 cm3 of gas is produced when an excess of Na is added to 0.001 mol of Y, when measured under room conditions. Assume that 1 mol of gas occupies 24.0 dm3 under room conditions. Deduce a possible structure of Y. Explain your answer. Z contains three types of atom: carbon, hydrogen and a halogen. The mass spectrum of Z is recorded. Fig.5.1 shows a section of the mass spectrum at m/e greater than 63. The fragment at m/e = 64 is the molecular ion peak. 2.2 33.3 relative abundance m/e Deduce the number of carbon atoms present in a molecule of Z using Fig.5.1. Show your working. Deduce which halogen is present in Z using Fig.5.1. Explain your answer. There are also peaks at m/e = 29 and m/e = 49. Suggest the formulae of these fragments. Deduce the name of Z. m/e = 29 m/e = 49 name of Z

22. Analytical techniques → 22.2. Mass spectrometry

14. Hydrocarbons → 14.2. Alkenes

2. Atoms, molecules and stoichiometry → 2.4. Reacting masses and volumes (of solutions and gases)

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