1.4. Ionisation energy
A subsection of Chemistry, 9701, through 1. Atomic structure
Listing 10 of 131 questions
In the Periodic Table, the p block contains elements whose outer electrons are found in the psubshell. Elements in the pblock show a general increase in first ionisation energy as the atomic number increases. Draw the shape of a p orbital.  Write an equation to show the first ionisation energy of silicon. Explain why there is a general increase in first ionisation energies of the elements across Period3. ElementA is in the pblock. The graph shows the successive ionisation energies for the removal of the first ten electrons of A. number of electrons removed ionisation energy State and explain the group of the Periodic Table that element A belongs to. group number explanation  Silicon is found in many compounds in the Earth’s crust. Silicon has only three naturally occurring isotopes, 28Si, 29Si and 30Si. The table shows data for 28Si, 29Si and 30Si. 28Si 29Si 30Si relative isotopic mass 28.0 29.0 30.0 A sample of silicon contains 92.2% 28Si. The total percentage abundance of 29Si and 30Si in the sample is 7.8%. The relative atomic mass, Ar, of silicon in the sample is 28.09. Calculate the percentage abundance of 30Si. Give your answer to one decimal place.  percentage abundance of 30Si = %  Silicon reacts with nitrogen gas to form Si3N4. Si3N4 is a solid with a melting point of 1900 °C. It is insoluble in water and does not conduct electricity when molten. Suggest the type of bonding in and structure of Si3N4. Explain your answer. Sulfur-containing compounds, such as C2H5SH, are found in fossil fuels, and produce SO2 when they are burned. Write the equation to show the complete combustion of C2H5SH. State why the presence of SO2 in the atmosphere has environmental consequences. Describe one of the consequences on the environment. SO2 can react with ozone, O3, to form SO3 in two different reactions. In one reaction, SO2 reacts with O3 until a dynamic equilibrium is established. SO2+ O3SO3+ O2State and explain the effect of an increase in pressure on the composition of the equilibrium mixture. In the other reaction, a different equilibrium is established at 300 K as shown. 3SO2+ O33SO3ΔH = +462.3 kJ mol–1 Suggest a temperature needed to increase the yield of SO3 at equilibrium. Explain your answer. 
9701_w19_qp_22
THEORY
2019
Paper 2, Variant 2
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Radium is a Group2 element. The predicted lattice energy, , of radium sulfide, RaS, is –2612 kJ mol–1. Define . Some data relating to radium and sulfur are listed. Select relevant data from this list for use in your answers to parts to . process value / kJ mol–1 enthalpy change for Ra→ Ra2++ 2e– +1619 first ionisation energy of sulfur +1000 second ionisation energy of sulfur +2260 first electron affinity of sulfur –200 second electron affinity of sulfur +532 enthalpy change for S8+ 2e– → S2–+555 lattice energy of RaS–2612 Write an equation for the process corresponding to the second electron affinity of sulfur. Include state symbols. Sulfur exists as S8 molecules in the solid state. Use the data in this question to calculate the enthalpy change for the reaction S8→8S.  enthalpy change = kJ mol–1 Calculate the standard enthalpy change of formation, , of radiumsulfide.  standard enthalpy change, = kJ mol–1 State the two major factors that affect the numerical magnitude of a lattice energy. For each factor you have identified in , state whether it tends to make the lattice energy of radiumsulfide more or less exothermic than that of sodiumchloride. Explain your answer. The lattice energies of sodiumchloride, NaCl, and radiumsulfide, RaS, are –771 kJ mol–1 and –2612 kJ mol–1, respectively. Identify the dominant factor in determining the relative numerical magnitudes of the lattice energies of radiumsulfide and sodiumchloride. Explain your answer.
9701_w21_qp_42
THEORY
2021
Paper 4, Variant 2
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