Title Feb-March_2025_9701_42_QP - Crack A Level.pdf ✅

2 © UCLES 2025 9701/42/F/M/25 1 Silver, Ag, is a metal in the d-block of the Periodic Table. (a) Silver can form compounds containing either Ag+ or Ag2+ ions. Explain why silver is a transition element. ................................................................................................................................................... ............................................................................................................................................. [1] (b) Table 1.1 gives data relevant to the Born–Haber cycle for silver(I) fluoride, AgF. Table 1.1 standard energy change value/ kJmol–1 first ionisation energy of silver +732 enthalpy change of atomisation of silver +289 enthalpy change of atomisation of fluorine +79 enthalpy change of formation of silver(I) fluoride –203 lattice energy of silver(I) fluoride –955 (i) Write equations for the standard enthalpy changes described. Include state symbols. • standard enthalpy change of atomisation of silver ........................................................................................................................................... • standard enthalpy change of formation of silver(I) fluoride ........................................................................................................................................... [2] (ii) Define lattice energy. ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2] * 0000800000002 * , , ĬÕĊ3⁄4Ġ ́íÈõÏĪÅĊÞü ̧þ× ĬÁĈùÖħôøáČĊÜùČĝoĞĂ ĥÕĥÕõμÅÕĥõåąąõĥμåÕ DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN
3 © UCLES 2025 9701/42/F/M/25 [Turn over (iii) Calculate the first electron affinity, EA1 , of fluorine, using data from Table 1.1. It may be helpful to draw a labelled energy cycle as part of the working for your answer. EA1 = .............................. kJmol–1 [2] (c) (i) Use the data in Table 1.2 to calculate the enthalpy change of solution, ΔHsol, of AgF(s). Table 1.2 energy change at 298K value/ kJmol–1 lattice energy of AgF(s) –955 enthalpy change of hydration of Ag+ (g) –464 enthalpy change of hydration of F– (g) –506 ΔHsol of AgF(s) = .............................. kJmol–1 [1] (ii) Use your answer to (c)(i) to suggest whether AgF is soluble in water at 298K. Explain your answer. ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [1] * 0000800000003 * , , Ĭ×Ċ3⁄4Ġ ́íÈõÏĪÅĊÞú ̧þ× ĬÁćúÎġðĈØî÷čÝô1oĎĂ ĥÕĕĕμÕåμõąõąąĕąõμÕ DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN